Diane Jean Moorcroft, 62, changed her name by deed poll to assume the identity of a dead landlady and opened bank accounts to convince solicitors she owned an upmarket home in Kensington.
She was helped in the scam by her Dubai-based daughter Laylah Scarlett De Cruz, 31, reportedly a model, who played a “pivotal" role in the deceit.
The pair now face jail after they were convicted at Southwark Crown Court of conspiracy to commit fraud .
In 2014, they conspired with others to rent a property in Kensington, west London, using fake documents, police said.
But when the tenancy of the property was secured, Moorcroft changed her name by deed poll to the genuine owner who had died.
She then travelled to Dubai where she opened bank accounts with a new UK passport in the dead landlady’s name.
Back in London, she applied for a loan of £1.2 million against the reported £3 million-valued property which was approved in October 2014 before funds were transferred to Moorcroft’s Dubai bank accounts.
The loan was later withdrawn in cash and the money has never been recovered.
Scotland Yard detectives launched an investigation later that month after the Land Registry flagged suspicious activity around the Kensington property.
Moorcroft, of Blackpool, was arrested in February 2015 at her home and De Cruz was arrested as she entered the UK from Dubai in May last year.
The pair were found guilty at Southwark Crown Court of conspiracy to commit fraud.
Detective Constable Richard Kirk, of the Met, said: "Having gained access to the property by renting it, Moorcroft duped a solicitor into believing that she was the rightful owner and signed documents to that effect.
"The suspects then approached a broker and obtained a bridging loan of £1.2 million against the property.
"De Cruz played a pivotal role, she recruited her mother and persuaded her to change her name to that of the deceased owner of the address and open bank accounts in that name.
"Having been promised a percentage of the proceeds of the fraud, Moorcroft willingly took part.”
De Cruz and Moorcroft were released on bail and will be sentenced on March 10.