Detectives hunting new leads in the Jill Dando murder inquiry have flown to Los Angeles to enlist the help of an expert on celebrity stalking.

LA's deputy district attorney, Rhonda Saunders, leads an anti-stalking unit which specialises in prosecuting fans who have become obsessed with Hollywood idols.

The Stalking and Assessment team was established following the 1991doorstep killing of television soap actress Rebecca Schaeffer.

So far it has pursued successful convictions on stalkers hounding Sylvester Stallone, Michael J Fox, Madonna and Kevin Costner.

More recently, the team was involved in securing a 25-year prison sentence on a man who plotted to assault director Steven Spielberg.

Scotland Yard detectives, increasingly desperate for leads to help them crack the high profile case, believe that Ms Saunders may be able to help build up a profile of Miss Dando's killer.

Their US inquiries come as Australian police interview a man reported to have been an obsessive fan of the presenter.

Ms Dando, 37, who presented the BBC's Crimewatch programme, was shot in the head at close range with a semi-automatic 9mm handgun outside her home in Fulham, west London, on 26 April last year.

Despite a massive murder inquiry, police have yet to pinpoint a motive or a suspect.

According to Ms Saunders, known in LA as the "Stalker Queen", detectives need to intensify their operation.

"I spoke with a detective several weeks ago and they had come out here to basically find out what we're doing here in California how we approach these types of cases," she told BBC Radio 4's Today programme.

"They are very different from what police officers are used to. They're very time intensive and it is sort of like a jigsaw puzzle where you need to get all the pieces and put it together.

"Police officers are used to crimes such as burglaries or robberies where they may interview one or two people, take a report and that's it. Then they send it to the prosecutor.

"With stalking they need to do a lot more work because if it is a true stalking case, generally it has taken place over a long period of time."

But, warns Ms Saunders, stalkers exhibit no obvious character traits.

"Anyone can be a stalker. We've had lawyers, judges, police officers, transients and doctors. There is no specific profile for a stalker.

"A lot of times these stalkers have no prior criminal histories. Sometimes they're in their 30s or 40s before they start their stalking activities, before they become obsessed.

"And I recently just prosecuted a case of a 74-year-old man who was stalking his ex-wife. He was trying to blow her up with pipe bombs, he blew up her truck and he blew up her motor home and prior to this activity he had led a blameless life.

"Anyone who is in front of the public can be the victim of an obsessed stalker. I think it goes back to that expression that familiarity breeds contempt.

"Nowadays with access to TV and the movies, people sit in front of their TV sets they see the same person there day after day and they feel as if they've had a relationship with them."

Australian police question 'fan

Meanwhile, Australian detectives have taken a statement from a British man who is reported to have been an obsessed fan of Miss Dando.

The 29-year-old man left the UK within days of her murder, it was reported locally.

A Scotland Yard spokesman said: "We have been in touch with New South Wales Police and inquiries have been made. We have no plans at present for detectives to visit Australia."