A newspaper was sent a chilling confession letter about plans by a local man to kill the person he blamed for his son’s death before taking his own life.

The Peterborough Telegraph received the nine-page letter by Roy Allison Snr detailing his plans to kill Duncan Bell then commit suicide to avenge the death of his son, also called Roy Allison.

The letter arrived at the paper’s Priestgate offices on Tuesday after the two bodies were found in Peterborough on Sunday and was also sent to 13 other recipients including the police.

Mr Allison Snr, 65, is believed to have stabbed Mr Bell in the heart on Sunday before hanging himself in the grounds of Peterborough Crematorium hours after the killing.

In his letter, Mr Allison Snr wrote that he thought Mr Bell, 36, had given his son drugs which led to his death on 21 March this year – the day after his 28th birthday.

He wrote: “When I lost my son, my grief was such that I just wanted to die and join him. I was in shock and disbelief.

“A few weeks on, I realised no matter what I wanted, I had to do for my son the right things and put our house in order.

“Duncan Bell, known recently as my son’s best friend… is one of the biggest dealers of drugs in this area. Duncan caused his death.”

Mr Allison wrote that he had kept in touch with Mr Bell after his son’s death so he could carry out his investigation.

He claimed that while drunk, Mr Bell had admitted guilt for the death because he had given drugs to Mr Allison Jnr.

He wrote: “The law is the law but justice is another matter. We don’t get justice. Duncan took our whole existence… and for that he will lose his life at my hand.

“Like he did my son, I will do to him and take it all away from him. I take my own justice.”

Telegraph editor Mark Edwards said:  “The letter came in our normal post and as soon as I read the first sentence it was apparent what it was and who it was from. We had broken the story online over the weekend so we knew who Roy Allison Sr was.

“The letter outlined his grief and goes into what he calls his own investigation into his son’s death . He draws his own conclusions, and then outlines what he is planning to do.

“He says he is going to take his own life and talks about ‘getting justice’ because he wasn’t confident in the normal process of justice.

“He claims Duncan Bell caused his son’s death and makes a lot of allegations based on conversations he had with Duncan Bell and others. He speaks of how he became convinced Duncan Bell was responsible for his son’s death and talks about getting justice for his son.

“It’s a very detailed letter, but he’s making a lot of assumptions. He is clearly a man tortured by grief who has decided on a violent conclusion to what he perceives as an injustice.”

Cambridgeshire Police have said they will examine the letter as part of the investigation into the two deaths.