The two girlfriends were cleared of the charges. File picture: PA

Two women accused of using insider information from an investment banker they both believed was their boyfriend were cleared by a jury today.

Jessica Mang, 29, and 44-year-old Christina Weckwerth had no idea of the existence of the other.

They were both acquitted of one count of insider dealing following a trial at Southwark Crown Court in London, the Financial Services Authority said.

The pair was alleged to have made “substantial profits” by using confidential details given to them by Thomas Ammann about a future company takeover.

Ammann, who worked at the London offices of Japanese bank Mizuho, was one of only a few people to know “price sensitive information” about the takeover of Dutch printing firm Oce by global electronics company Canon.

He allegedly passed information to Weckwerth, 44, and 29-year-old Mang, and encouraged them to trade in the shares of Oce prior to the acquisition being announced, the FSA said.

Both considered Ammann, 39, to be their boyfriend and had no idea of the existence of the other.

Weckwerth, who is from Germany, was said to have made one million euros in profit through the sale of the shares, while Mang pocketed £29,000, the FSA said.

Ammann has pleaded guilty to two counts of insider dealing and two counts of encouraging insider dealing, the FSA said.

He will be sentenced on a date to be confirmed.

Tracey McDermott, the FSA’s director of enforcement and financial crime, said: “As an approved person Ammann knew he could not deal using the inside information he had without arousing suspicion but he thought that by getting his girlfriends to trade instead they could avoid being caught. He was wrong, and he now faces the consequences.

“The charges against Weckwerth and Mang were serious and we considered that the evidence provided a proper basis to put the case before a jury for them to decide.

“Criminal prosecutions are integral to the FSA’s long-term strategy of delivering credible deterrence and combating city wrongdoing.”

The FSA made no criticism of Mizuho International plc.