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".