Ontario's police watchdog will not charge Ottawa police officers after a key suspect in a London, Ont., cellphone slaying drowned in the Rideau River as he ran from police.

Muhab Sultan, a 23-year-old from Calgary, had been wanted for second-degree murder in the death of Jeremy Cook.

Cook, 18, of Brampton, Ont., was shot and killed in a London parking lot on June 14 while trying to track down his lost cellphone.

Toronto Muhab Sultanaly Sultan

Muhab Sultan, 23, of Calgary was wanted for second-degree murder in connection with Jeremy Cook's shooting death when he drowned in the Rideau River in Ottawa. (London Police Service)

Cook had inadvertently left his cellphone in a taxi, and had used a mobile-tracking app to trace it to an address in London's north end.

Police have said Cook was confronted by three men in a car when he arrived at the address. When the vehicle tried to drive away, Cook grabbed on to the driver's side door.

Shots were fired and Cook died from multiple gun wounds, police say.

Sultan questioned 10 days after shooting

Ten days later, Sultan was stopped and questioned in the ByWard Market in downtown Ottawa, along with an associate, as he drove an unregistered vehicle, according to a report from the Ontario Special Investigations Unit released Friday.

Sultan fled the scene in the vehicle and struck a police officer, the report said.

Officers later caught up to the vehicle and arrested the associate, but Sultan fled on foot, hiding in the backyard shed of a home on Marlborough Avenue.

The report said the homeowner found Sultan and called police, but the suspect ran off and jumped into the Rideau River.

Police officers 'acted valiantly,' SIU says

When officers arrived, the report goes on to say they heard Sultan's screams for help as he was in the middle of the river and had difficulties swimming. Officers then jumped in to help Sultan but he disappeared under the water before they could reach him.

Muhamed Ibrahim Sail

Muhamed Ibrahim Sail, of Calgary, was charged with second-degree murder in the death of Jeremy Cook in London, Ont.

"[The subject officers]

acted valiantly by jumping into the river in an effort to save Mr. Sultan from drowning," said Joseph Martino, SIU acting director, in a news release.

"They were tantalizingly close to reaching him before he dipped out of sight below the water's surface."

Sultan's body was recovered three days later by police divers downstream from where he went under.

In the news release, Martino said Sultan's death was the "product of his own misadventure … an ill-advised decision to enter the water in an effort to avoid police apprehension."

The SIU investigation included interviews with six residents and four witness officers, as well as police officers' notes.

Mohamed Ibrahim Sail, also of Calgary, turned himself in to London police in July and he faces one charge of second-degree murder connected to Cook's death.