The newspaper's report cited a person familiar with the matter as saying BP's internal review of its currency trading operations in London was "ongoing."
The FT reported that the investigation, which is not being carried out by any financial regulator, was prompted after a Bloomberg report cited undated messages sent to BP's employees by a network of foreign-exchange traders at four major banks about planned currency trades "sometimes hours before they happened."
Asked to comment on the FT report, BP issued an emailed statement that said: "Following regulatory market (not into BP) investigations regarding the FX markets, we conducted a review into our activities in this area. BP's FX desk has relationships (as a customer) with 26 relationship banks, including JP Morgan, Citibank and Barclays."
Last month, financial regulators in the United States, the U.K. and Switzerland fined six major banks a total of $4.3 billion (3 billion pounds) for failing to stop traders from trying to manipulate the foreign exchange market. The fines followed a year-long global investigation.
The European Commission also has been investigating allegations that BP manipulated oil and biofuel prices.
(Reporting by Ankush Sharma in Bengaluru; Editing by David Gregorio)