Senators investigating the unauthorized release of a confidential parliamentary report on medical assistance in dying believe the leak may have originated with a member of the House of Commons rather than the Senate.Sen. Peter Harder, chair of the Senate rules committee, said his review of media coverage surrounding the leaked document led him to suspect someone on the Commons side of a joint parliamentary committee was responsible."My reading of the leaked stories would suggest at least to me that the unauthorized disclosure came from a member of the House of Commons," Harder told a committee hearing."It was obvious to me," he added.Blacklock's Reporter said the controversy centres on a confidential report prepared by the Special Joint Committee on Medical Assistance in Dying.Details of the report appeared in the National Post on June 15 and CBC News on June 16, before the document had been formally tabled in Parliament.The Senate investigation was launched following a June 16 complaint by then-Senator Pamela Wallin of Saskatchewan, who said the unauthorized disclosure undermined parliamentary procedures and public confidence."It breaks trust," Wallin testified."It is disrespectful, and that does reinforce the notion of breaking trust, but it also impacts the public's assessment of the issue itself, when certain material is leaked."Harder said the reporting suggested the source was connected to the House of Commons."Reading the National Post story, it was obvious to me that the leak did not come from the Senate but probably from a House of Commons participant," he said."Just for the record, would you share that view?" Harder asked Wallin."Yes," she replied.Neither senator identified a suspected leaker by name.Liberal MP Marcus Powlowski (Thunder Bay-Rainy River, Ont.), who served as the Commons co-chair of the joint committee, has declined to testify before the Senate investigation.Wallin criticized his conduct during the committee's proceedings, describing some of his interactions with witnesses as inappropriate."The House co-chair offered I think, and this is my opinion, inappropriate interventions leading or challenging or criticizing witnesses on occasion," she said..Wallin also pointed to the timing of the media coverage and Powlowski's comments in the National Post."I saw this report in the National Post which extensively quoted the House co-chair of the committee expressing his views," she testified.She said the situation was particularly troubling because the report had not yet been formally presented to Parliament."The leak was very troubling because he had spoken to media extensively and the report had not yet been tabled at that point," she said.Wallin described the committee's internal proceedings as difficult and said concerns about the process were not adequately addressed."The chair was very dismissive of any questions we were asking about the process in there," she said."I am not going to repeat conversations or what I heard because these are in camera meetings, but it was chaotic and exclusionary."Sen. Percy Downe of Prince Edward Island condemned the unauthorized disclosure, accusing those responsible of using confidential parliamentary material to advance their own positions."Honourable members have acted in a dishonourable manner by leaking this," Downe said."They obviously do it for their own personal agenda which is to get their point of view out early and even leak information to the media that was erroneous."However, senators acknowledged that identifying the individual responsible could prove impossible.Sen. Toni Varone of Ontario questioned whether the committee should concentrate on finding the source or strengthening parliamentary rules to prevent future disclosures."Are we here to put our Columbo hat on and conduct this investigation and find out where the leak was?" Varone asked."Or are we here to assess the rules we have and change them to prevent this kind of issue from happening again?"Harder acknowledged the difficulties involved in tracing confidential documents once they have been distributed to parliamentarians."It would be very difficult if not impossible – I would say impossible – to determine the source of the leak," he replied."We should move on, in my view, to determine the nature of the harm."Jodi Turner, assistant clerk of the Senate, told the committee that existing administrative systems can track the distribution of confidential documents but cannot determine what recipients subsequently do with them."Once a document has been properly provided to an authorized recipient, administration officials do not control how that recipient stores, prints, uses or discusses the document," Turner said.She explained that parliamentarians receiving confidential material are reminded of their obligation to protect it and warned that unauthorized disclosures could constitute a breach of parliamentary privilege.Such breaches can trigger formal investigations..Turner said no administrative safeguards could completely eliminate the possibility of confidential parliamentary information reaching the media."The reality is no administrative system can 100% guarantee that outcome," she told senators.The investigation has not established who leaked the assisted dying report, and no evidence presented at the hearing conclusively identified an individual responsible.With the source potentially impossible to determine, senators are now considering whether existing parliamentary rules provide sufficient protection for confidential committee proceedings.