Heathrow has suspended the security passes of around 300 workers of Sodexo, the company which supplies airline lounge services.
Sodexo said it’s a precautionary measure and follows news that police are investigating a scam involving airside security passes at the airport.
A Metropolitan Police spokesman said: "Officers from the Met's Aviation Policing Command are investigating an allegation of fraud, reported to them on July 28.
"Detectives arrested two women from Surrey, aged 24 and 20, on suspicion of fraud and money laundering on August 3.
"They have been arrested in relation to an allegation that money has been fraudulently taken from a bank account.
"Other matters have come to light during the inquiries and form part of the ongoing investigation."
Scotland Yard said the women have been released on bail until late November.
A spokesman for Heathrow Airport said: "Our top priority is the security and safety of our passengers and colleagues and we have taken appropriate action until the investigation is completed.”
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