Police hunting a man linked to four brutal murders in North Yorkshire raided a house today in a town close to where the victims were killed.

Police swooped on the property in Abbots Road, Selby, as they stepped up their search for prime suspect Mark Hobson, who has been linked by detectives to the murders of twin sisters and an elderly couple.

Speaking at a packed press conference this morning, Detective Superintendent Javad Ali said detectives had visited the house following reports that Hobson had been sighted at the address.

He said the divorced father of three was not at the property.

Two women were arrested in connection with the two double murder inquiries.

Mr Ali said that Hobson remained at large.

He added that North Yorkshire Police were doing everything possible to try to locate the former bin man.

He said: ''We have searched a number of locations where we thought he may have gone, CCTV tapes have been seized from petrol stations, town centres and other locations and taxi drivers have been put on alert. Friends and associates of Hobson's have been visited and it's possible he is staying in one place or moving about.''

Mr Ali stressed that Hobson would eventually be tracked down and described the will of his force to find the man as ''awesome''.

He said: ''We are doing everything we can to find Mark Hobson. We are gathering evidence and searching both murder scenes but it remains of vital importance that Mark Hobson is found and found quickly.''

When quizzed over how he thought the prime suspect in the two double murders was moving around he said he was keeping an open mind. ''He could be moving around by foot, by car or even by bike. I want people to keep an open mind, we just don't know at this stage.''

Mark Hobson has not been seen since his girlfriend Claire Sanderson, 27, and her twin sister Diane were found murdered at his flat in Camblesforth, near Selby on Sunday morning.

Yesterday the investigation took a dramatic twist when Hobson was linked to a second double murder after a man fitting his description was spotted near the home of victims John Britton, 80 and his wife Joan, 82, just 25 miles away in Strensall.

Police said evidence recovered from the scene also suggested the murders were linked.

However, police again said today that no links between the Brittons, the Sandersons or Hobson have been established.

Today the daughter of the couple, Catherine Wilkins expressed her shock at her parents' brutal deaths.

She said: ''We are very shocked and distressed about the sudden and unexplained deaths of our mum and dad Joan and Jim Britton.

''If anyone has any information which can help the police we would urge them to come forward so that the person or persons responsible for this appalling crime can be caught as soon as possible.

''We are a private family and wish to be left alone to be able to come to terms with our loss.''