A man found dead after his neighbour died from a cardiac arrest had suffered stab wounds.
The body of Richard Wight, 55, was found in his home in Eagle Lane, Braintree, Essex, on Sunday afternoon after paramedics were called to the home of his neighbour Alan Taylor, 59.
There had been a long-running dispute between the men and, in 2007, Mr Wight was given an Asbo preventing him from harassing Mr Taylor.
Police are treating the deaths as suspicious but are not looking for anybody else.
An Essex Police spokesman said: "Provisional results of the post-mortem on Alan Taylor have concluded that he died from natural causes. Provisional results of the post-mortem of Richard Wight have concluded that he died from stab wounds."
A spokesman for the Crown Prosecution Service has confirmed Mr Wight received a six-month conditional discharge in January 2009 after admitting that he breached the terms of his Asbo, issued in 2007. The breach came after he used offensive words or behaviour towards Mr Taylor.
Neighbours also claimed that Mr Wight attacked Mr Taylor in 2002, but the CPS had no record of this incident. Wight is believed to have served time in prison.
Residents said the men had been embroiled in a long-running dispute over a parking space.
One resident, who did not wish to be named, said: "They certainly didn't get on and people are saying that it got worse over Christmas."
A police spokesman said the investigation would centre upon both men's movements since January 1.