Concerns are growing for a missing oil industry executive after a fraudster tried to sell her flat by posing as her brother.
Carole Waugh, 50, has not been seen by her family since mid-April and financial activity linked to her identity has become "incrementally more suspicious" since then, Detective Chief Inspector John McFarlane said.
"Very substantial sums of money" have been stolen since the businesswoman vanished - she was last seen by relatives at a family party at Easter.
At least three women have tried to impersonate her - one at the Westfield shopping centre in west London on July 13.
A man has also posed as her brother Chris at her flat in Marylebone, central London, in an attempt to sell it.
DCI McFarlane said: "From the inquiries since Carole has gone missing, we've established that there have been at least three women impersonating her at various locations, at various financial institutions and other premises.
"We know that there has been a man, who we haven't as yet identified, who has been impersonating Chris who was endeavouring to raise finances and engage in the selling of her flat."
The man was impersonating Chris up until late June, he said.
A "significant amount" of the businesswoman's personal property has also gone missing, but DCI McFarlane would not reveal what has disappeared.
Her brother Chris Waugh, 53, who lives in Cumbria, said it was "a very distressing moment" to discover the conman had posed as him.
He came down to London with his wife and daughter to help detectives with their investigation.