Detective Superintendent Gordon Lang told the Mail it was the worst he had come across in his 21-year career. And his comments come as police revealed they are now treating the case as attempted murder.

Victim Michael Webb is critically ill in hospital where he is under sedation after being doused with petrol and set on fire outside his home in Annandale Crescent, in Hartlepool, in the early hours of Tuesday morning.

A team of 22 officers are investigating the attack.

Det Supt Gordon Lang, of the Cleveland Police murder investigation team, said: "There is only one word for the attack and that is horrific. In my experience I have never seen anything like it.

"This is something up until now unheard of in the whole of the force area, indeed something not experienced in the North East.

"How any human being can be so callous to another escapes me.

"The person responsible for an attack as violent and horrific as this has no place in the Hartlepool community.

"You cannot justify this level of violence, irrespective of motive, this level of violence is outrageous.

"It is no coincidence that the murder investigation team are investigating, that's the level of seriousness we are applying to the case."

Police say the incident followed a number of disturbances outside the victim's home the day before he was attacked.

They want to speak to four people believed to have been involved in a "heated argument" outside Mr Webb's home who they believe could help with the inquiry.

Mr Webb is in a critical condition at Newcastle's RVI hospital with 40 per cent burns. Police are assisting his partner Stephanie Bates who they described as "very upset".

Det Supt Lang added: "We know that during the day there were a number of disturbances in Annandale Crescent involving the victim.

"We are particularly keen to trace four people who were involved in a heated argument with the victim outside the property at around 10.30pm on Monday, August 4.

"We believe they may hold some vital information and I would also appeal to members of the community who have any information to come forward and contact us, however insignificant they may think it is."

Anyone with information can contact Hartlepool Police on (01642) 302126 or Crimestoppers confidentially on 0800 555111.