The province's Special Investigations Unit has cleared two Toronto police officers in the death of a man who resisted following a routine traffic stop last year.

The man who died is Junior Manon, 18. He had been driving westbound on Steeles Avenue West near Keele Street when a marked police car stopped his vehicle at about 6:30 p.m. on May 5, 2010.

An officer did a computer check of Manon and then attempted to arrest him for being in breach of a probation condition, according to a news release issued Thursday by the SIU.

"The officer attempted to handcuff Mr. Manon, but Mr. Manon broke free and ran from the officer," it said.

The chase took the two officers and Manon on to the grounds of York University. When the officers caught up with him, a struggle ensued.

One officer said Manon punched him a number of times and that he responded with his own punches.

"The second officer attempted to subdue Mr. Manon by wrapping his arms around his head and upper arm area. One of his arms may have been placed briefly around Mr. Manon's neck," the SIU said.

"Mr. Manon continued to struggle and one or the other of the subject officers placed their weight on Mr. Manon's upper body at varying times in an effort to control him," it said.

"At one point, Mr. Manon attempted to get up as if he was doing a push up with his arms, but the weight from the officers prohibited him from doing so."

Other officers arrived. As they handcuffed Manon, they noticed he was unresponsive. They placed him in the recovery position.

Paramedics arrived at approximately 6:50 p.m. By that time, Manon was VSA, or "vital signs absent," the SIU said.

Toronto EMS transported Manon to the Finch site of the Humber River Regional Hospital, where doctors pronounced him dead at 7:42 p.m.

'Positional asphyxia'

The SIU received an autopsy report in late November, 2010. It found the cause of death was positional asphyxia.

Asphyxia occurs when the body is deprived of oxygen. Positional asphyxia means the person was placed in a position that interfered with their breathing.

"During a struggle with the two subject officers after he fell or was taken to the ground, pressure was placed on his chest in a manner that could have caused it to compress and interfere with his breathing," the SIU wrote.

No medical evidence supports an alternative theory of death, such as a deliberate act of choking, it said.

"Given the level of resistance from Mr. Manon and the medical finding that his cause of death was unrelated to neck injury, I am of the view that the force used to arrest him was not excessive in these circumstances," wrote SIU director Ian Scott.

“His demise by means of positional asphyxia following exertion and struggle was tragic, but the subject officers cannot be held criminally liable for this unintended consequence of what was probably a lawful apprehension."

The SIU is an arm's-length provincial agency that reviews cases where people have suffered serious injuries or died as a result of contact with police.

The SIU said it designated two officers as subjects, both of whom provided statements. Twenty-six other officers were designated as witnesses. The SIU interviewed another 18 civilians.

Five of its investigators and another two forensic investigators worked on the case.

Manon, a former student of Westview Centennial School who was known as Tubz in the neighbourhood, did not have any known chronic medical problems, according to a  friend who spoke with CTV Toronto back in May.