VANCOUVER -- B.C.'s police watchdog is seeking witnesses to an incident in Tsawwassen that ended in a man's death.

The Independent Investigations Office is hoping to speak to the driver and passenger of a newer-model Mazda CX3 or similar who dropped off a man at the ferry terminal on May 29 between 11:06 and 11:10 p.m. The man was in his early 40s and was wearing khaki pants, a hat, black windbreaker and carrying a backpack.

Investigators are also hoping to speak to anyone who saw or interacted with the man at the ferry terminal between 11:10 and 11:30 p.m. that night.

The IIO looks into incidents involving police officers that result in death or serious harm.

Delta police were called to the terminal around 11:30 p.m. for reports that a man had stolen a taxi. Two people were trying to hire the taxi when it was stolen, but were not inside the vehicle at the time, according to police.

Officers encountered a vehicle they believed to be the stolen taxi on the causeway, police said. The driver got out and "engaged with police," who called additional officers to the scene, according to the Delta Police Department.

"During an interaction with police shortly thereafter, the man sustained serious injuries," the IIO said in a statement. He was transported to hospital, where he was later pronounced dead.​

Delta police did not elaborate on the circumstances that led to the man's death, but a news release from the IIO at the time of the incident indicated officers arrested the man before he died.

With files from CTV News Vancouver's Jen St. Denis and Ian Holliday