The fresh leads were revealed at the inquest into her death, opened and adjourned on Wednesday at Hammersmith and Fulham Coroner's Court in west London.

Detective Chief Inspector Hamish Campbell told the inquest a man resembling an E-fit of the suspect was seen getting on a number 74 bus at 1145 BST - just after the presenter was shot near her west London home on 26 April.

He was reportedly sweating heavily and speaking into a mobile phone. The bus took him from Fulham Palace Road to Putney Bridge tube station.

Police are reportedly studying CCTV footage taken in and around the station in the hope of spotting either their suspect or an accomplice, who may have been driving a blue Range Rover in the area.

The BBC's Stephen Cape: The man was said to be breathless and sweating at the bus stop

Mr Campbell told coroner Dr John Burton that Ms Dando's body could not be released for burial, because it may eventually be needed for independent examination by a legal defence team.

Mr Burton said he would not be making a tribute to the presenter, because the public reaction after her death had been sufficient tribute in itself.

The bus lead came as police made contact with several people who were standing at a bus-stop minutes after the shooting and near where her suspected killer was spotted.

Speaking after the adjournment, Mr Campbell said the suspect was seen by a bus driver.

The BBC's Jon Brain: "The lack of an obvious motive is hindering the investigation"

Another witness described a man "running for all his life" from near Ms Dando's home on Gowan Avenue to Bishop's Park. The man was reportedly almost hit by a van on his way across Fulham Palace Road.

Mr Campbell said the "unascertainable" motive for the popular presenter's murder was the greatest hindrance to progress in the inquiry.

He appealed for members of the public to come forward with fresh information, no matter how insignicant they thought it might be.

He also appealed for anyone who had seen Ms Dando buying two Dover sole fish from a shop on Fulham Road just before she was killed.

'Worthwhile exercise'

Police spent Tuesday distributing leaflets in the streets near the former Crimewatch presenter's home - hoping to jog someone's memory.

Police have issued this E-fit of their prime suspect

The exercise has been a considerable success, with several of the six or seven people who were believed to be standing at a nearby bustop being identified.

Police say they have received a "steady stream" of calls since releasing CCTV images of Miss Dando taken less than an hour before she was shot.

She was pictured shopping at Kings Mall shopping centre in Hammersmith, west London, at 1055 BST.

She went there after leaving her fiancé Dr Alan Farthing's home in nearby Chiswick.