An estate agent at Foxtons who started warning landlords about a gang specialising in sub-letting scams received anonymous late-night threats on her mobile phone.
She was told in one call that she would have acid thrown in her face.
A friend told The Sunday Times that the agent had been “severely traumatised”.
The Foxtons agent was part of a group investigating the gang after police declined to do so.
The Sunday Times yesterday carried a major story about the “sophisticated gang” which targets luxury rental properties.
The gang’s members rent properties, apparently as legitimate tenants.
They then sub-let the property, collecting rent from tenants that the landlord knows nothing about, while the landlords themselves receive no payment.
The gang takes advantage of the sheer length of time it takes for evictions to be obtained.
One landlord said: “They stopped paying the rent after two months but it took me almost a year and cost me £70,000 to evict them.”
According to the story, the police regard the matter to be a civil one, prompting a group of letting agents, landlords and concerned neighbours to start their own investigations.
Gang members go to considerable lengths to get past tenancy referencing and checking processes.
The paper quotes a fashion consultancy whose boss found that the fraudsters had forged references, bank statements and payslips in her company’s name.
Patrick Bullick, managing director of estate agency Stanley Chelsea, said that the problem was “rife” across London.
He said: “The rise of Airbnb and other letting sites has facilitated this criminality. Thousands of properties are being misused in this way in central London.”
Kim Taylor-Smith, deputy leader of Kensington & Chelsea Council, said: “It cannot be right that criminals roam the districts of London and the police just look the other way.”