LONDON/NEW YORK (Reuters) - The U.S. Department of Justice (DoJ) on Tuesday charged a Barclays foreign exchange trader based in New York over his alleged role in a scheme to defraud a client of the bank, the DoJ said.

The Barclays logo is seen in front of displayed stock graph in this illustration taken June 21, 2017. REUTERS/Dado Ruvic/Illustration

Robert Bogucki, the former head of foreign exchange trading in New York for the British bank, is accused of manipulating forex options before a large trade by computer and software maker Hewlett-Packard Company (HP) in 2011, using a practice known as “front-running.”

A Barclays spokesman said on Wednesday that the bank had been co-operating with the DoJ investigation and that the incident involved a single transaction that pre-dated improvements to its procedures.

Bogucki, a U.S. citizen who lives in New York, pleaded not guilty in Brooklyn federal court on Wednesday and was released on bail.

Bogucki’s lawyer, Sean Hecker, said in a statement: “Put simply, Mr Bogucki is innocent.”

“He tried hard to do right by HP while following the rules that governed market-makers in foreign exchange for many years. This action is nothing more than an unfair and misguided attempt to rewrite those longstanding rules.”

Bogucki is still employed by Barclays but has been on leave since November 2016, according to a source familiar with the matter.

His case will proceed in San Jose, California federal court, where the indictment against him was filed.

According to the indictment, Bogucki misused information provided to him by HP before the company’s planned acquisition of a British-based company.

HP hired Barclays to execute 6 billion pounds ($8.3 billion) worth of foreign exchange options as part of that deal. Bogucki is alleged to have made trades ahead of the deal that benefited Barclays at HP’s expense.

“Robert Bogucki and others allegedly not only betrayed his client’s confidences, but also risked undermining public trust in the foreign exchange options market,” acting Assistant Attorney General John Cronan said in a statement on Tuesday.

The indictment alleges that Bogucki and other unnamed Barclays bankers sought to enrich the bank and themselves.

Bogucki is charged with one count of conspiracy and six counts of wire fraud.

The indictment is the second in recent months brought against the head of a foreign exchange desk at a major international bank in the United States.

A jury in October found former HSBC executive Mark Johnson guilty of defrauding Cairn Energy Plc in a $3.5 billion currency trade in 2011.