Detectives hunting for missing eight-year-old Sarah Payne have released an e-fit picture of a man they want to question in connection with her disappearance.

The computer-generated image is the likeness of a man seen with a young girl fitting Sarah's description at a service station and police believe it could be the most significant lead yet in the ten-day inquiry.

Chief Inspector Mike Alderson, the inquiry team spokes-man, said he believed it would narrow down the search for the man, who was spotted with the girl at Granada Services, Knutsford, on the M6 motorway.

The girl, who was said to look upset, told a woman at the service station her name was Sarah.

Sarah Payne disappeared 11 days ago during a visit to her grandparents at Kings-ton, near Worthing.

Mr Alderson said of the e-fit picture: "It should rule some people out of the inquiry and therefore will narrow down our search for this man. It's a strong lead and e-fits normally generate a huge amount of calls."

Assistant Chief Constable Nigel Yeo said police had so far not been contacted by the man seen with the "upset" young girl or any of his friends or relatives.

He said: "The problem with him not coming forward is it remains a totally unanswered question. He may simply not have seen the coverage so again, as with everything else, I have to keep an open mind."

Police also scrambled a helicopter yesterday after an unconfirmed sighting of the youngster with a man in south Wales.

Sussex Police said they received a report of a girl fitting Sarah's description with a man outside a pub in the village of Cilfynydd.

A spokesman said: "The helicopter has spent an hour scouring the area but as yet the sighting has not been confirmed."

Detectives revealed earlier that they had taken 800 calls from the public since the possible sighting at the service station.

Officers also said there had been possible sightings as far afield as Greece and Israel.

The man seen in Wales was in his thirties with scruffy hair and sideburns. He wore a light-coloured jacket and faded jeans.

The police spokesman said the girl was between eight and nine and wore ill-fitting new shoes.

She was seen sitting outside a pub in Cilfynydd eating sweets.

Local shopkeeper Alan Phillips, 50, said: "A policewoman came in and asked me if she had seen a man with a young girl.

"She said he had a teddy boy look about him but I was not able to help them."