The City of London Police is carrying out an inquiry amid claims officers accepted gifts worth thousands of pounds from the Church of Scientology.
Tom Cruise is an outspoken advocate of the religion
Some received free invitations to a charity dinner, with Tom Cruise as the guest of honour, details from a Freedom of Information Act request showed.
More than 20 officers were allegedly targeted over a 15-month period.
A City of London Police spokesman said it was ensuring all members of staff were aware of its hospitality policy.
He said: "We are conducting a review to ensure that all members of staff are aware of the force policy on accepting hospitality and to assess whether clarification of amendment... is necessary".