Three ex-traders at the heart of criminal investigations over their participation in the chatroom ‘The Cartel’ have pleaded not guilty to charges of rigging foreign exchange rates in the latest case of global forex market manipulation.

The three men are Chris Ashton, former Global Head of Spot Trading at Barclays, ex-JP Morgan dealer Richard Usher, and Rohan Ramchandani, formerly of Citigroup. They reached an agreement with US prosecutors last month to surrender voluntarily and are facing the charges at a New York court hearing.

The former traders appeared today before US District Judge Richard Berman in Manhattan, all charged with one count of conspiracy to restrain trade from the end of 2007 through to the beginning of 2013. The goal of the conspiracy was to suppress and eliminate competition in the trading of the euro and the dollar in the US, UK and Switzerland.

For this purpose, they allegedly created a chat group dubbed ‘The Cartel’ to coordinate the trading of US dollars and euros and manipulate the prices of the exchange rates, according to the charges.

The federal judge ordered the trio to next appear after four months then stand trial at a Manhattan court on June 4, 2018. Berman has set bail at $200,000 for Ashton, $1 million for Ramchandani and $650,000 for Usher.

The indictments against the UK citizens came after US authorities came under open criticism for not prosecuting any traders involved in the FX rigging scandal since it broke out in 2013, although they did impose multi-billion dollar fines against major banks.

Back in March 2016, Britain’s Serious Fraud Office looked at the same evidence and decided not to bring charges, citing insufficient evidence for a realistic prospect of conviction.

Lawyers for the traders criticized the US for moving forward with the case but said that that they will voluntarily travel to New York to defend themselves and will deny any wrongdoing.