Mouncey 38, was found with a head wound in a hotel bathroom in Pattaya, a tourist mecca on the east coast of the Gulf of Thailand on Monday night, Pattaya One reported.
Mr Mouncey, a British passport holder, was discovered in his third floor apartment by a housekeeper at P Place Apartments, Pattaya People reported.
His passport showed he was born in Dunedin.
“CCTV was checked and Mr. Mouncey was seen to arrive at his room with a Thai woman at approximately 3am, reported Pattaya One.
“He left 20 minutes later with her, and after seeing her leave on a motorbike taxi Mr Mouncey was seen to re-enter his apartment alone.
“It was confirmed that no other individuals entered the apartment prior to the discovery of his body.”
It was reported Mr Mouncey’s body was sent to Police Forensic Institute in Bangkok for a post-mortem examination, and police were speculating that Mr Mouncey may have suffered from an acute medical problem which caused him to collapse.
“It is thought he was able to recover but the head-injury sustained in the fall may have caused his eventual death,” reports said.