A former care home inspector has been arrested over allegations that she pressured homes into giving money in exchange for "favourable" reports.
The woman, who used to work for the Care Quality Commission (CQC), was arrested on suspicion of bribery and money laundering.
The CQC said it sacked her after an investigation and had informed the police.
It said the woman had failed the organisation and people in care.
The unnamed 43-year-old was arrested on Thursday morning at her home in Northamptonshire.
City of London Police said care homes were "pressurised into paying fees for favourable inspection report".
Detective Inspector James Clancey said: "We are working closely with CQC to thoroughly investigate these allegations."
The CQC said it had a "zero tolerance policy" towards fraudulent or dishonest behaviour and that it expected "extremely high standards" from its inspectors.
Louise Guss, director of governance and legal services at the CQC, said: "This inspector has failed the organisation, failed the providers who rely on us to act fairly and impartially, and - most importantly - failed in their responsibility to protect people who use services through identification of poor care.
"Unfortunately, in any large workforce there is a risk that a tiny minority may act in a way that betrays the principles of their colleagues and of the organisation as a whole, which is what has happened here.
"Having investigated allegations made to us about this inspector and found these were substantiated, we terminated their employment with immediate effect and referred the matter to the police."