A young British father is dead after taking part in an internet craze that involves people punching each other until one of them gives up.
The Telegraph reported that Tom Main collapsed after being punched in the chest while playing "Punch4Punch".
Mr Main suffered a heart attack and died a shortly after being taken to hospital.
A 20-year-old man was arrested by police and released on bail.
Mr Main leaves behind a four-year-old daughter.
In Punch4Punch, two participants punch each other in turns until one of them gives up.
The losing player then has to complete a punishment like drinking shots and the whole thing is usually filmed and posted on social media.
According to the Telegraph, Mr Main’s brother Roy criticised the people who filmed the fight on their mobile phones and did nothing to stop it.
He wrote on Facebook “I love you Tommy boy."
"I had to say good by to my little brother today for the last time."
Punch4Punch is similar to the NekNominate online game which was linked to deaths earlier this year
A police spokesman told the Telegraph "Police were called by London Ambulance Service at 12.44am on Sunday to a residential address in The Nursery, Erith, to reports of a man collapsed."
The spokesman told the Telegraph the incident was being treated as an unexplained death rather than suspicious.