Proceedings were paused at the public inquiry looking into the federal government's use of the Emergencies Act on Wednesday afternoon after a medical incident.
A lawyer representing the Public Order Emergency Commission collapsed while he was questioning Ontario's deputy solicitor general, the second witness of the day.
Emergency responders were called to the Library and Archives Canada building in downtown Ottawa and proceedings were stopped. lawyers and spectators were cleared from the hearing room.
Gabriel Poliquin was in the early stages of examining Mario Di Tommaso when he collapsed to the floor. His condition is unclear.
Poliquin is part of a team of lawyers working for the commission, which is tasked with investigating the circumstances surrounding the Liberal government's decision to invoke the Emergencies Act for the first time in Canadian history on Feb. 14.
The commission will switch witnesses when proceedings resume. Ian Freeman of the Ontario Ministry of Transportation will testify, with Di Tommaso resuming his testimony tomorrow.
Public hearings, which began Oct. 13 and are set to continue until Nov. 25, have focused this week on testimony about border blockades in Windsor, Ont., and Coutts, Alta.
Earlier Wednesday, the mayor of Coutts said RCMP appeared to be caught off-guard by a protest blockade of the U.S-Canada border crossing last winter, even though he had warned the provincial government it could happen.
Jim Willett sent an email to then-premier Jason Kenney and the provincial solicitor general on Jan. 27 to warn about the potential of a blockade, and was assured the RCMP had been alerted.
He said he was worried about maintaining vital access to the highway in the small border town of 245 people, and he also warned the protest could result in an international incident.
On Jan. 29 a large convoy of trucks gathered at the border, with some driving onto the median and ditches and blocking the road.
The mayor said the RCMP didn't establish a large police presence until three days later.