The Sunday Mirror newspaper says detectives are investigating whether the blonde-haired person seen in Gowan Avenue, where Ms Dando was shot, could have been a woman in a man's suit.

Police have never been able to say for certain that the person who killed her was male. The newspaper says a source close to the investigation has confirmed that following a review of the case, "the murder squad are taking the possibility of a female killer seriously".

Ms Dando was killed on 26 April outside her house in Fulham, west London.

At 1040 BST that morning, window cleaner Alan Taylor, who was working nearby, saw a person with light coloured hair, smartly dressed in a light grey two-piece suit talking into a mobile phone.

This was about the time Ms Dando would have pulled up outside her front door, the newspaper reports.

Jill Dando: No one has yet been charged for her murder

The suspect was seen loitering outside Ms Dando's house and was described as looking like an estate agent.

Mr Taylor was the only person to see the person he described, and told them the person was stocky, 5ft 8in tall, with blonde hair.

But the newspaper says he has since complained that police did not take his description seriously, or made sufficient appeals to find them.

He believes the person he saw "could be female".

"I can't believe the police haven't considered this before," he told The Sunday Mirror.

'Police ignored description'

"From what I told them the person I saw could well have been a big, frumpy woman. It could be a disguise."

He said police had "ignored" what he told them, and that the description he gave them was the opposite of the "guy they have been looking for".

"I'd heard all this talk about a dark-headed guy seen running up Gowan Avenue but the person I saw standing outside Miss Dando's house was definitely blonde," he said.

The police description of the suspect is 5ft 11 with dark hair, also wearing a suit.

A police source is quoted as telling the newspaper: "The window cleaner told us it was a person with blonde hair - this quite conceivably be a woman with short blonde hair dress in men's clothing for disguise."

The Sun newspaper offered a £100,000 reward last week to help catch the killer, on the 100th day since her death.