It is said that two players from the team had complained about breathing difficulties and were rushed to a leading private hospital in Colombo on Sunday, a day after Durham City Clem's Pirates played a friendly match against CR&FC in Colombo on Saturday (12).
"We would also like to take this opportunity to thank everyone for the many messages of sympathy and support that have been received from our members, friends and the wider rugby family; they are very much appreciated at this hard time".
The pair had been touring the country with Durham-based Clems Pirates RFC when they visited the club in Colombo.
A Foreign & Commonwealth Office spokesperson told CNN it was "in contact with the Sri Lankan hospital, police and coroner", as well as assisting the families of both men.
Clem Pirates were in Colombo on tour, having arrived last Wednesday, before facing Ceylonese Rugby and Football Club (CR & FC).
Both men were admitted to hospital on Sunday after they started suffering from breathing problems following a night out.
"Thoughts and prayers at this hard time".
Durham County Councillor David Boyes said Durham City RFC was a very well organised, well-equipped organisation which oversaw a number of teams.
"They are very much appreciated at this hard time", he said.
"I really feel for the families, being that far away and knowing that a family member has died must be bad", he said.
"They do a lot of good work raising money for charity and introducing people to rugby", he said.
One local report said the family of the dead man, aged 26, would travel to Sri Lanka from Northern Ireland.