A decorated search and rescue serviceman from RNAS Culdrose killed himself just hours after being told he would be investigated by police.

Lieutenant Commander Timothy Barker, an observer with the 771 squadron at the Helston naval base, was found in the spare bedroom of his home in Esmonde Road with a gas mask on his face, which was connected to helium canisters normally used to blow up balloons.

Earlier that day the 40-year-old father of four had received a telephone call from a police detective, saying the force was to launch an investigation into allegations made against him, which have not been made public.

The circumstances were revealed during an inquest into his death on October 17 last year.

Lt Cdr Barker, who had served two deployments in Afghanistan and also at the Navy's search and rescue base at Prestwick in Scotland, was found by his wife Sarah and step father Peter Oliver.

Mr Oliver said his stepson used to visit him quite regularly, but in the weeks leading up to his death he had not seen him, which he described as “unusual.”

“I was speaking to Sarah; she knew that he was quite worked up by different things - stressed. She never really told me much about it,” he told the inquest.

On the day of Lt Cdr Barker's death, Mr Oliver had been at the farm where he used to live when he received a phone call from Sarah saying she needed to see him.

He returned home, where she told him she was unable to get hold of her husband and was worried about him.

After 30 minutes they went together to the home she shared with Lt Cdr Barker, where his car was unexpectedly parked outside.

Mrs Barker headed in first and then waved her step father-in-law inside, who found his stepson on the bed wearing the mask.

“He looked so peaceful,” he said.

Mr Oliver ripped of the mask and began CPR, on the instruction of the emergency call handler, but Lt Cdr Barker was later pronounced dead at 6.15pm.

A note was subsequently discovered on the bedside cabinet, which both the family and police read as a suicide note.

Lt Cdr Barker's death was automatically referred to the police professional standards office and the Independent Police Complaints Commission, but there were no findings.

The cause of death was given as suffocation due to helium inhalation, with coroner Andrew Cox recording that Lt Cdr Barker took his own life.

Mr Cox said: “It seems to me that Mr Barker has reacted extremely to the complaint made against him during the afternoon of October 17, 2013 and has deliberately and intentionally attempted to take his own life - an attempt that has proved to be successful.”

Speaking after the inquest Andrew Murray, a friend of Lt Cdr Barker and his family, said the serviceman had saved the lives of people in both Scotland and Cornwall, adding: “This is just an unfortunate end to a very good life. He should be remembered for the good things he's done, not just the final ten minutes.”

Mr Barker flew more than 290 rescue operations during his career and was among a helicopter crew presented with an award for heroism, following a difficult rescue involving a woman trapped in a sea cave near Newquay in 2007.