Police sergeant Steve Miles committed suicide after becoming depressed when his sister took her own life, making him the sixth person in his family to do so, an inquest ruled.

Mr Miles, 52, a sergeant with the Ministry of Justice armed police at MoD Corsham, was found dead on the sofa of his home on May 12 last year from numerous lacerations.

He became depressed and took six months off work after his sister committed suicide in September 2009. He had just returned to work when he took his own life.

His wife Karen wept as the assistant deputy coroner for Swindon and Wiltshire, Claire Balysz, delivered a verdict of suicide last Wednesday at an inquest in Trowbridge.

Sgt Miles, of The Pippin, Calne, served in the Army before becoming a police officer. Both of his parents committed suicide, as well as his niece and a brother-in-law, over the past 20 years.

But in September 2009 his sister Jessica took her own life, leading Mr Miles into a spiral that led to his death.

He went on sick leave and, over six months, changed to the point where he was unrecognisable to friends. He was treated by GPs and hospital staff and was due to see a psychiatrist.

Friend and colleague PC Lee Maplesden said: “He was as normal as normal is until that day [of his sister’s death]. But he felt responsible for looking after his sisters and even more so for Jessica because she was the youngest.

“The absence of a father figure had put the responsibility on Steve.”

He met PC Maplesden before Christmas for a coffee in Chippenham, by which time he had lost three stone in weight. PC Maplesden said: “He was almost unrecognisable. He came straight up to me and I had to do a double take at who I was looking at.”

Sgt Miles had also become obsessed with the Mayan Calendar and codes he believed were written into the Bible. When he returned to work on a phasing-in basis in April, colleagues said he was not the same man who had gone on sick leave.

Inspector Paul Kerry said: “He wasn’t the Steve I had known for 14 years. He just appeared totally different. He was hard to talk to and was fixated on the Mayan Calendar.”

Dr Balysz said: “Steve had a very turbulent upbringing.

“Although he didn’t leave a suicide note he left a very detailed account of his life. He had previously discussed suicide. Therefore my conclusion is that Steve took his own life.”