UK authorities are now investigating the possibility of criminal fraud in the foreign exchange markets.

The director of the UK Serious Fraud Office (SFO) said Monday that it has formally opened a criminal investigation into allegations of fraudulent conduct in the foreign exchange market. The SFO, which is responsible for investigating and prosecuting serious and complex fraud, bribery and corruption cases in the UK, did not give any further details about its planned inquiry.

Various other authorities in the U.S. and Europe have been engaged in their own investigations into allegations of misconduct in foreign exchange markets for some time. These follow the numerous investigations into the manipulation of financial benchmarks, such as LIBOR.

Earlier this year, the Bank of England reported that it had suspended an employee pending an investigation into compliance with its internal control processes, amid a review into allegations that officials at the central bank knew about manipulation in the forex market. The outcome of that investigation has yet to be revealed, and no disciplinary action has been taken against any member of Bank staff, it said.

Other authorities investigating possible misconduct in the forex market include U.S. authorities, the UK’s Financial Conduct Authority (FCA) and Swiss regulators, which are looking into allegations of collusion and market manipulation. At this point, no formal charges have been brought.