The brother of failed businessman Christopher Foster, who killed his wife and daughter before setting fire to their Shropshire home, has claimed he was sexually abused by him when they were younger.

Andrew Foster, who lives in Wolverhampton, claimed the abuse happened from the time his brother was about 15 or 16 and he was about 11 years old. He said he believes his brother suffered from a personality disorder.

Christopher shot his wife Jill and their 15-year-old daughter Kirstie in August 2008 along with the family pets before setting fire to his home, Osbaston House, near Oswestry. He died in the blaze.

Andrew, who revealed new details about his brother in an article in a Sunday newspaper, also said he was making complaints about West Mercia Police.

He said he felt the police investigation was rushed and incomplete.

He added: “When we were told about the fire, two family liaison officers came to the house. I was obviously a suspect. I explained I had very little to do with him.

“I told the officer that when I was 11 and Chris was 15 or 16, Chris told me about the facts of life. This continued on and off and eventually he showed me pornographic magazines. After a while he started to sexually abuse me.

“This explains why Chris and I didn’t see each other much. The abuse was about control. He always denied it but there was a pattern in Chris’s life and it revolved around controlling other people.

Andrew also admitted he had contemplated committing suicide. “I did feel suicidal last year,” he said. “There were days when I was trying so hard to get someone to take notice of all the issues surrounding Chris’s death that I thought about going to Osbaston House and hanging myself. Just to get people to recognise what we’ve been through.”

He handed in a 120-page document containing 63 complaints in June to the Independent Police Complaints Commission which has now been passed to West Mercia Police. He said:“I am not forcing blame. I am saying there was evidence to say he did threaten people.”

Sarah Buxton, for West Mercia Police, confirmed the complaint had been received and was being investigated. She said the force would reply directly to Andrew Foster.

She added the investigation surrounding events at Osbaston House ‘was one of the most complex and challenging cases West Mercia Police has ever dealt with’.

She said: “The investigation team were praised by the coroner and Detective Chief Inspector Jon Groves, now retired, received a Chief Constable’s Commendation for his work.”