Police investigating the disappearance of Carole Waugh have re-arrested Rakesh Bhayani on suspicion of murder.
Unemployed Bhayani, 40, is being interviewed at a south London police station.
He also faces three charges of conspiracy to commit fraud by false representation worth around £280,000, linked to use of Ms Waugh's identity, police said.
Bhayani, from Chamberlayne Avenue, Wembley, previously appeared via video link at Westminster Magistrates' Court on July 24 and was remanded in custody to appear again at Southwark Crown Court on September 25.
Police found Ms Waugh's badly-decomposed body in a car at a lock-up garage in New Malden on August 2. It is thought she died from a single stab wound.
The 50-year-old oil executive, originally from Durham, was reported missing on May 7 and had not been seen by her family since mid-April.
Nicholas Kutner, 47, is being held in custody on fraud charges after being arrested on suspicion of murder and kidnap on August 1.
He is accused of pretending to be Chris Waugh, Ms Waugh's brother, in a bid to sell her London home.
He also faces two charges relating to renting her property at Tressard Court and a fourth of unlawfully withdrawing funds from Miss Waugh's bank account.
Ms Waugh had lived and worked in Libya for a number of years, but returned to London in 2008 and would regularly visit relatives in Durham and Cumbria.
Her former boss, Stuart Anderson, told journalists she had fled Libya after being threatened by someone in Colonel Muammar Gaddafi's regime, but a Scotland Yard spokesman said inquiries are focused in London.
Detectives said she met men through a variety of internet sites, including dating websites, and they were investigating the possibility that she might have been an escort.
So far, a total of 10 people have been arrested in connection with the inquiry into Miss Waugh's disappearance.
