TRAGIC twin Diane Sanderson may have driven to her own death after a telephone call from wanted man Mark Hobson, police revealed today.

Detective Superintendent Javad Ali, the man leading North Yorkshire's biggest murder investigation, said Diane had a phone call from Hobson last Saturday at about 7pm.

Dressed for a night out, and due to meet a friend, Diane set off from her family home at East Cowick, near Goole, in her light blue Peugeot 306, 20 minutes later.

She was never seen alive again.

Mr Ali appealed for anyone who saw Diane's car, a light blue Peugeot 306, registration number T149 KRP, to contact them.

Chillingly, it is now thought Hobson went drinking with a pal while the twins' bodies were in bin bags at his flat in Camblesforth, near Selby.

He was seen in the Comus Inn pub, in Camblesforth, between 2pm and 6.40pm last Saturday.

Hobson met a friend at the Swan Inn, Brayton, near Selby, later that evening.

The pair then visited the Comus Inn, only 100 yards from Hobson's flat, at about 10pm.

They stayed until closing time and left at about 11.15pm.

Forensic science tests on Diane's sister Claire have now shown she died between Sunday, July 11, and Thursday, July 15.

The sisters' bodies were found last Sunday at the home Claire shared with Mark Hobson, 34. The bodies of James Britton, 80, and his wife Joan, 82, were discovered hours later at their home in Strensall, near York.

Mr Ali said that tonight and tomorrow morning, police would mount an operation aimed at gathering vital information from the public. Thousands of racegoers were this afternoon being given details about Hobson. Police have produced 10,000 leaflets and a team of 40 officers was distributing them among the Knavesmire crowd.

York Racecourse spokesman James Brennan said: "We are happy to work with the police in distributing the leaflets and to do what we can. There's a wide gathering of people here - it provides an opportunity for police."

A loudhailer van covered with photographs of Hobson was due to be at the races from noon today, and it was touring Strensall, Camblesforth and Selby until 10pm.

Det Supt Ali said: : "Mark Hobson is a dangerous man. It's essential that we speak to him, but on no account should any member of the public approach him.

"We are working round the clock and this will continue until we find him.

"Our hunt is relentless and we will find him.

"My advice to him is: 'Give yourself up and do it now.'"

Officers from eight different forces are assisting in the murder inquiry, and detectives are drawing on experience from officers involved in the high-profile Soham, Barry Prudom and Fred West cases.

Officers from another force are assisting in the policing of a race meeting at York Racecourse today, so that North Yorkshire officers do not have to be taken off ongoing work on the Hobson inquiry.

Police officers have extended their fingertip search at Strensall to land beyond the Britton's garden boundary, searching for anything which might assist in their inquiries including a possible murder weapon.

Meanwhile, a York taxi driver believes he may have given a lift to Hobson on Sunday afternoon - hours after the Strensall couple died.

The Fleetways driver, who does not wish to be named, took a man of Hobson's appearance from the firm's offices in Queen Street, near York Railway Station, to Clifton.

He later saw a photograph of Hobson and realised his passenger looked very similar, and called police. Officers say there have been more than 1,000 "sightings" from all over Britain, and even from as far away as Dublin and New Zealand.

Police believe Hobson has little money and no change of clothes.

Detectives have appealed to boat owners and people on the waterways to keep a look-out for Hobson, as he had said in the past how he would like to own a narrow boat.

Patrick and Bonnie Murray, who have moored their narrow boat, Drifter, on the River Ouse, near Lendal Bridge, vowed to keep their eyes open.

"We will keep a look-out for him and be on our guard," said Patrick.

Alan and Nancy Fowlie, from Northumberland, who are in York with their river craft, Firefly, said they would "spread the word" among the river

community.

Updated: 11:55 Saturday, July 24, 2004