An Australian woman has denied any knowledge about the disappearance of British toddler Madeleine McCann after a friend identified her as a mystery witness in the case, a report said yesterday.

"I have no connection to the little girl," Judith Aron, 53, told Fairfax Media from her home in Melbourne.

Private detectives last week said they were seeking a "Victoria Beckham lookalike" with an Australian accent who spoke to a British man outside a bar in Barcelona three days after Madeleine vanished in Portugal in 2007.

She allegedly asked him whether he was "here to deliver my new daughter", before realising he was not the man she was looking for.

Fairfax reported that a friend of Ms Aron had told police she believed the Melbourne woman was the person depicted in an identikit sketch released by the British investigators, who are working for Madeleine's parents.

But Ms Aron, who speaks fluent Spanish and has a five-year-old daughter, said it was a case of mistaken identity.

"I'm 53 years old and I certainly don't look like a Spice Girl," she said.

"I'm shocked that anybody may have thought that I have some connection to this case. I can't understand how it may have happened. I can honestly say I have no connection to the little girl.

"I haven't left Australia since 2000, so there's no way I could have been in Portugal or Spain around the time she went missing."

Madeleine was nearly four when she went missing from her family's holiday apartment in Praia da Luz, a resort in the Algarve, on May 3, 2007 while her parents dined with friends nearby.