I would just like to quote from page 52 of the The Power of Parliamentary Houses to Send for Persons, Papers & Records by Derek Lee. The top couple of paragraphs read:
The only occasion when the Canadian House of Commons imprisoned a person was in 1913, in respect of an individual (Mr. Connolly) who refused to provide documents ordered by a committee....
And it's been quoted here:
[Mr. Connolly's counsel] read a statement...explaining that the books also contained private business matters unrelated to the concerns of the committee, which if made public would prejudice other clients of Mr. Connolly. The House ordered the books to be produced and delivered to the custody of the Clerk of the House.... A House or committee need not simply demand a copy of a document, or the production of the original by the witnesses upon examination; it may also demand “control” over the document.
This is open to us. I respect the right and the desire of Canada Post to keep things as tight as possible, but at this stage, in order to preserve the legitimacy of our report, we need access to these documents, and I can't stress that any more strongly than I have.