There is an official legal way to request information about status of your case to sponsor spouse to Canada. You can send request CAIPS, or GCMS, or FOSS.
CAIPS и GCMS - are for cases reviewed by visa offices outside Canada, when FOSS - is for cases reviewed "inside Canada".
There are two mjor ways to request information. First is particular for imigration cases (CAIPS), and secodn is universal (GCMS). Me, myself, I use first, CAIPS - is it's old title, in 2013 only this form (and name) has been changed four times. And actually pretty mush tired to rebuild the web-site to reflect those changes :))).
Usually the request is made by Sponsor. But if sponsor can not, then you need somebody who lives in Canada (and who you trust, of course). He must be a citizen of Canada or have a status of Permanent Resident.
Items "2.Method-1" и "3.Method-2" - select one. You should do only one of them. Result will be the same. I usually do "Method-1", because it's more specific for immigration, probably be handled faster. Form for Method-1 (CAIPS) often changed, when form for Method-2 (GCMS) almost never been changed.
So, to request CAIPS-GCMS-FOSS you should prepare:
- Get Money Order in your bank (or write a check) for 5 dollars.
- Method-1: CAIPS-FOSS: Fill in Form IMM5563B - the actual request.
- Method-2: GCMS: Fill in TBC-350-57 - the actual request.
- Fill in Form IMM5744E - sponsored spouse's consent for an access to information.
- If sponsored spouse has children 18 years old or older, then each of them also has to fill in IMM5475E.
- Sponsor must get a photocopy of Canadian passport or other document that confirm sponsor's status of citizen or permanent resident of Canada.
Note: If sponsored spouse has dependend children younger than 18 years old - they don't need to fill in anything and they are not mentioned anywhere in the request.
The request papers should be sent to the address:
Thierry Cadieux
A/Access to Information and Privacy Coordinator
Narono Building
360 Laurier Avenue West, Room B-1027
Ottawa, Ontario, K1A 1L1
Telephone: 613-957-6512
Facsimile: 613-957-6517
This email address is being protected from spambots. You need JavaScript enabled to view it.
No need for explanation letter.
Useful links:
Source for all the information: Access to Information - the legal paper is very big and complicated, you can find official web-site
http://www.tbs-sct.gc.ca/atip-aiprp/index-eng.asp
Address and name where to send the request (in case if it's changed) is on the Form itself at the very end, links to the forms in item 2 and 3. The direct link:
http://www.tbs-sct.gc.ca/atip-aiprp/apps/coords/index-eng.asp#c
scroll down to the Title - Citizenship and Immigration Canada
1. Money Order for request CAIPS-FOSS-GCMS to sponsor spouse to Canada.
- You can get it in your bank, it must be in the name of (do not sign it on the back side):
Receiver General of Canada
and attached to other papers.
(or cheque): If insead of Money Order you decided to send personal cheque, then just write the cheque from your cheque book. No big difference between MO and cheque, except the detail that Money Order is handled about two weeks faster (cheque needs confirmation).
2. Request CAIPS-FOSS to sponsor spouse to Canada.
Form IMM5563B - use link to download:
http://www.cic.gc.ca/english/pdf/kits/forms/IMM5563E.pdf
Here is example how to fill in the form:
In Section А: check boxes...
1.Access to Information Act, there are two ways to request the info, just we use this one, it's usual and we always use it,
2.English or French - it's your choice,
3.E-mail this way is much faster than the second on a CD disk,
4.No most likely you will be requesting info about your spouse or for your friends,
4.Consent included because it's not for yourself then we need consent from the person to open the info you are requesting, you can find consent example in items 4 and 5 below, 
In Section В: check boxes...
1.I am a Canadaian citizen or permanent resident..., to be eligible to make the request you must be a citizen or a permanent resident of Canada,
Proof included, you must provide evidence, it is described in item 6 below,
2.Public, this is closest category for us,
3.Business name, leave it empty, it's Ok, this field is not for us,
4.Family name, here is a Sponsor's last name, or last name of the friend who makes the request for you,
5.Given name, here is a Sponsor's first name, or first name of the friend who makes the request for you,
6.Mailing address, here is Sponsor's address, or address of the friend who make request for you,
7.Telephone ..., here is Sponsor's telephone, or phone of the friend who make request for you, it is important to mention your phone here, for example they call me twice when something in the request was wrong or their rules were changed,
8.E-mail address, here is Sponsor's E-mail, or E-mail of the friend who make request for you, if you mention it here then all communication will be via E-mail, that is significantly speed up the process, 
In Section C and D: check boxes in ...
1.Family name, here is sponsored Spouse last name, it must be identical to forms sent to sponsotship your spouse to Canada,
2.Given name, here is sponsored Spouse first name, and again, it must be identical to forms sent to sponsotship your spouse to Canada,
3.Date of birth, here is sponsored Spouse date of birth, also, it must be identical to forms sent to sponsotship your spouse to Canada, there is a button - click and select from pop-up calendar,
4.А) Electronic files, we request only ELECTRONIC copy,
4.А) Sponsorship file, this is our category,
4.А) File number, if you know you immigration file number then write it here, it started with letter "В" and eight digits after, it is assigned to the file when the file arrived and first reviewed in embassy (visa office), if you don't know the number - leave it empty - they will find by "name + last name + date of birth",
4.B) Physical files, NEVER CHECK ANYTHING HERE! THIS IS A REQUEST FOR PHYSICAL FILES - IT WILL ADD DELAY OF THREE-FOUR MONTHS TO YOUR PROCESS!
5.А)Select category...you:, check Sponsor - if you are a Sponsor and sending the request, but if you are a friend sending request then check Other,
5.В)Select category...you requesting:, Select Sponsored - if this is a request about your spouse,
Секция D: Signature and Date, sign and write today date, 
3. Request GCMS to sponsor your spouse to Canada.
(!) If you have prepared form by item "2. Method-1. CAIPS." - then you don't need this form! Proceed to item 4. immediately.
Form TBC-350-57 you can dowload it by the link:
http://www.tbs-sct.gc.ca/tbsf-fsct/350-57-eng.rtf - RTF file, I recomend to use this one because you can save it and correct later or use it again,
http://www.tbs-sct.gc.ca/tbsf-fsct/350-57-eng.pdf - PDF file
Example how to fill in the form - see below.
You start with - in the first box fill in with pen or use computer - the phrase:
I would like to request a current copy of all notes related to the processing of the permanent resident visa of Jane Doe (here is full name of sponsored spouse, ). She is being sponsored by her spouse, John Doe (here is full name of Sponsor). The visa is being processed in the Moscow office (write here your city of local embassy, Kiev or other). John Doe's client ID number is 12345678 (this is - if you have the number). Jane's client ID number is 87654321 (this is - if you have the number). Jane's paper file number is B012345678 this is - if you have the numberо). Jane's date of birth is 15 of April, 1980 (sponsored Spouse date of birth).
On the picture below - there is no date of birth, this is a mistake. Date of Birth is highly recomended because it is often used to identify sponsored spouse and find related file.
Check box with "Receive copies of originals". Leave empty "Examine". In "Name of Applicant" - here is name of Sponsor. Below - Sponsor's address and phone. Address must be Canadian. Next, check box - "Canadian citizen, permanent resident". And last - sign and write today date.
4. and 5. Form IMM5744E for request of CAIPS-GCMS-FOSS to sponsor spouse to Canada. For Spouse (4) and for her(his) dependend child who is 18 years old or older (5).
This Form is prepared by sponsored spouse. And if there is a child 18 years old or older then every child must prepare same form as well, all fields are the same, just the name and birthday are of the child.
You can download teh Form IMM5744E by the link:
http://www.cic.gc.ca/english/pdf/kits/forms/IMM5744E.pdf
Lets check the example - how to fill in the Form.
1. Fill in Last name and First name, and date of birth of sponsored Spouse.
2. This box - leave empty, it's not for our category of immigration.
3. Fill in Last name and First name and E-mail of Sponsor (or friend, who requests for you the CAIPS).
4. Check two boxes YES - that you allow to open our info to Sponsor, and, second is wyou allow to send this info to Sponsor's E-mail.
Next - sign the Form and write today date, by selecting from pop-up calendar.
The Form is ready.
6. Photocopy of Sponsor's canadian passport to request CAIPS-GCMS-FOSS to sponsor Spouse to Canada.
... or any other document that prove Sponsot is a Canadian citizen or permanent resident. Make a copy only of the first two pages where is the photo, last and first name of Sponsor. This is a simple photocopy, no need to notarize it or register, just put it into envelope with all other Forms.
No need for any other letter or explanation. All papers mentioned above should be put into envelope and sent to address(same as above):
Public Rights Administration
Citizenship and Immigration Canada
Narono Building
360 Laurier Avenue West, 10th floor
Ottawa, Ontario
K1A 1L1
Today I received my CAIPS, that I fill in by the example above. From the day they received my request till the day I found answer in my E-mail - it took one month exactly.
On the web-site of "Artefact" - artefact.lib.ru - there is a slightly different example how to request CAIPS:
here is his version how to make the request - it's a little different than mine above.
Explanation of abbreviation used in CAIPS you can find on "Artefact" web-site -
here is my copy of explanation - it's a PDF file in archive.
