MONTREAL -- Prime Minister Justin Trudeau said he is "concerned" about the arrest of a Montreal man wrongly accused of attempting to murder a police officer and kept in detention for almost a week.

Trudeau described the case of Mamadi III Fara Camara as "troubling" and said he has confidence Quebec authorities will do what is needed to figure out what happened.

"I know the responsible authorities are very aware of the pressure that will be on them to figure out exactly what went wrong and to fully answer the questions of friends and family and citizens who are extremely worried about this troubling incident," he told reporters Friday.

Shortly afterwards, Montreal's police chief publicly apologized to Camara and said new evidence has conclusively cleared him, though the investigation continues.

Camara was arrested Jan. 28, after a police officer was allegedly disarmed and attacked following a traffic stop in Montreal's Parc Extension borough -- located in the Papineau riding Trudeau represents.

The man spent almost a week in detention when prosecutors on Wednesday stayed all the charges after they said evidence had surfaced absolving him.

it's still unclear what happened on the night in question. On Friday morning, Montreal police said the investigation into the assault is continuing and that they've found a vehicle they said they believe was driven by a suspect in the case.

In a statement issued Friday morning, the office of the director of prosecutions said that prosecutors "in principle" are required to have a complete case before charges are laid. But, it added, it's "not exceptional" for charges to be laid early in the interest of public safety.

Audrey Roy-Cloutier, spokeswoman for the director of prosecutions, wrote that police arrested Camara based on information provided by the officer who was attacked and from circumstantial evidence. She said the charges were filed at the request of police.

Roy-Cloutier said prosecutors received new evidence Feb. 3 and that after reviewing it, came to the conclusion it was no longer possible to support the charges against Camara. She confirmed Friday evening that the changes have now been not just stayed, but dropped.

Politicians and civil rights groups on Thursday demanded an independent investigation to determine how Camara ended up in jail for almost a week before the charges were dropped. Mayor Valerie Plante's denounced Camara's detention as "unacceptable" and said any eventual independent investigation should examine whether racial profiling played a part.

Yves Francoeur, head of the Montreal police brotherhood, accused the mayor of "political interference" in the ongoing police investigation. In a letter to Plante Friday, the union head said her decision to discuss racial profiling in connection with the case was "extremely deplorable."

"In doing so, you throw oil on the fire, undermine the social climate and complicate even more the task of those responsible for ensuring the safety of Montrealers," Francoeur wrote.

Later on Friday, a community organization in Parc Extension held a protest in solidarity with Camara.

This report by The Canadian Press was first published Feb. 5, 2021.