Police are investigating the mystery death of a Canadian tourist found with a mark on his neck while 'play fighting' with his friends in Bangkok.

Christopher Tuca, 19, had been staying in an apartment with two friends in the upmarket Silom area of the Thai capital but collapsed on Wednesday afternoon May 3.

Police responded to an emergency call and arrived at the Altitude Samyan-Silom building shortly after 2:30 pm local time

Christopher, from Vancouver, British Columbia, was pronounced dead at the scene. Officers found asthma medication in the room but they also identified an apparent injury on Christopher's neck which forensic teams are now investigating.

They believe the teenager had been play-fighting with his friends, with a policeman saying they had been 'running around, chasing and teasing' before the incident.

Police Lieutenant Colonel Tachakorn Chorlamyai of Bangrak Police Station said he responded to the incident by dispatching forensics police, forensics doctors, and paramedics.

He said: 'The tourist was identified as Christopher Andrew Tuca. He was found deceased on his bed, wearing a white t-shirt, cream trousers, and white shoes.

'When searching the room, a large red bag containing asthma medication was found on the bed. The items were collected as evidence.'

According to a preliminary investigation, Tuca was found to have been staying at the condominium with two friends, as they had travelled to Bangkok together for a holiday.

Police said that before the incident, Christopher had been inside the apartment preparing to go out later in the afternoon.

He was allegedly 'running around, chasing and teasing' with his friend.

However, Christopher's friends said he suddenly went into shock and experienced breathing difficulties before falling unconscious.

Officers believe his underlying medical condition may have been a contributing factor to his death.

They said they would investigate the unexplained death and have collected evidence from the scene.

Police Lieutenant Colonel Tachakorn added: 'The deceased was in the apartment running around, chasing and teasing each other with his friend.

'There was a mark on the tourist's neck similar to a friction mark from human contact. This was photogaphed. A belt and medicine have also been collected from the room.

'We are now waiting for the results of the autopsy to determine the exact cause of death.'