The U.K.'s Serious Fraud Office is gathering information about possible rigging of the foreign exchange market, the latest sign of the seriousness of the global probe into currencies trading.

"We are receiving and examining complex data on this topic," a spokeswoman at the SFO told The Wall Street Journal Sunday.

"If and when we open a criminal investigation, that decision will be announced in the usual way," she said.

The involvement of the U.K.'s top antifraud agency in the global currencies probe was announced last week by Martin Wheatley, chief executive of the U.K. Financial Conduct Authority, who said his agency was working with the SFO on the matter.

Since last year, authorities in the U.S., Asia and Europe have been investigating possible misconduct in the GBP5.3 trillion-a-day foreign exchange market, including possible efforts by traders to manipulate the market to their unfair advantage.

The FCA has said that the investigation has led to "unprecedented global cooperation" between global financial regulators, including requests from other regulators in 52 instances solely related to the foreign exchange probe.

Since the start of the currencies market investigation, more than 30 staff in several locations have been fired or suspended by top currencies dealing banks.

Regulators and bankers have said the currencies probe could be as big or bigger than the investigation into efforts to rig a key interest-rate benchmark, the London interbank offered rate, or Libor. Ten firms have settled Libor-rigging allegations or been fined by authorities, while prosecutors in the U.S. and U.K. have filed criminal charges against more than a dozen individuals.

The FCA said earlier thisyear that the outcome of its currencies investigation is unlikely to be public before 2015.

Write to Chiara Albanese at chiara.albanese@wsj.com

Subscribe to WSJ: http://online.wsj.com?mod=djnwires

(END) Dow Jones Newswires

July 21, 2014 01:05 ET (05:05 GMT)

Copyright (c) 2014 Dow Jones & Company, Inc.