An expat couple from Norfolk who were 'living their dream' in Cyprus died of carbon monoxide poisoning after a mystery fault with their gas heater, an inquest heard.

Retired builder Kenneth Lincoln, 59, and his 56-year-old wife Linda were found unconscious on the sofa of their apartment in the town of Paralimni in the east of the Mediterranean island on February 2.

Mrs Lincoln worked as a clerk at a private school called the Xenion School, and a colleague went to the apartment and raised the alarm after she failed to report to work, an inquest at Norfolk Coroner's Court in Norwich heard on Thursday.

Norfolk area coroner Yvonne Blake, reading from a translated report written by police in Cyprus, said the couple had emigrated to Cyprus in 2005.

Mr Lincoln was born in Mulbarton, near Norwich, and Mrs Lincoln was born in Caston, in mid Norfolk.

A colleague went to the couple's apartment after Mrs Lincoln failed to report to work.

'He realised there was condensation on the window and immediately contacted the police,' said Ms Blake. 'After opening the shutters of the back door he discovered Mr and Mrs Lincoln were sitting unconscious on the sofa.'

She said the colleague checked an outdoor gas cylinder, saw the switch was in the on position and turned it off, then alerted emergency services.

Police forced entry and there was a strong smell of gas, Ms Blake said.

A post-mortem examination found no external injuries, and blood tests showed the couple had died of carbon monoxide poisoning.

'The trouble is no one has been able to find out why the gas was leaking into the house,' said Ms Blake. 'They looked at it and said the heater wasn't damaged but there was a strong smell of gas in the house.

'They were enjoying living there. Mrs Lincoln had a job and that's how they were found.'

She said there was no evidence of violence, nothing was missing and she was 'completely satisfied there's no evidence whatsoever that suicide is even an issue here'.

Recording an open conclusion, Ms Blake told two relatives who attended the brief hearing: 'I just don't know how they were poisoned by it.

'I'm very sorry for your loss. It's a horrible thing to happen, especially as they appeared to be living their dream.'

The relatives that attended the hearing did not wish to comment.