TORONTO - Ontario government officials say it's up to police to decide whether charges of criminal negligence should be laid in the deaths of four migrant workers in Toronto.

The four men died and a fifth man is in intensive care with two fractured legs and a broken spine after they plummeted 13 storeys to the ground on Christmas Eve.

The accident happened when scaffolding broke as the men were making balcony repairs at an apartment building.

On Tuesday, Ontario Federation of Labour president Sid Ryan called on Ontario's attorney general to investigate whether criminal negligence was involved in the incident.

He cited Bill C-45, known as the Westray Bill, that allows criminal charges to be laid if a company causes death or serious injury due to negligence.

But Ministry of Labour spokesman Matt Blajer said Wednesday it's up to police, not the attorney general, to look into the matter.

"The police are currently conducting an investigation to determine if any Criminal Code provisions have been violated and we're providing assistance to the Toronto Police Service," said Blajer.

Rosemary Parker, a spokeswoman for the attorney general, said Wednesday the attorney general does not conduct investigations and cannot direct an investigation to take place. She too said it's in the hands of police and the Labour Ministry.

"It is important that the process be allowed to be carried out. They will then make any decisions with respect to next steps based on their findings," she said.

Blajer said it's an active investigation but could not say how long the probe by Labour Ministry inspectors might take.

"It was a fairly complex accident and we have to determine exactly what happened," Blajer said.

The Labour Ministry's probe is focusing on whether the Occupational Health and Safety Act was violated.

Ryan has questioned how much training experience the workers had.

In 2008, in Ontario alone, there were 488 fatality claims and 317,031 claims for work-related injuries and diseases reported to the Workplace Safety and Insurance Board, Ryan said.