Two brothers who worked in print rooms at major investment banks passed on confidential information to traders as part of a £1 million “insider dealing ring”, a court heard.

Ali Mustafa, a print room assistant at UBS, and his brother Ersin, who worked as an operations manager in the confidential print room at JP Morgan Cazenove, stole documents on secret takeovers or mergers and passed them on to five traders, Southwark Crown Court heard.

Using data obtained from the banks, the men made a profit of more than £1 million from trading in the shares of Reuters, Premier Oil, Vega, Enodis, Thus and Biffa.

Alongside his brother Ersin, who did not appear before the jury, Ali Mustafa passed the information to five traders - Pardip Saini, Paresh Shah, Neten Shah, Bijal Shah and Truptesh Patel - who placed spread bets on the companies.

It is alleged they used broker Mitesh Shah, who was “in on it and would not blow the whistle on what was going on”, to make the bets, prosecutor Michael Bowes QC said.

”The allegations are that these defendants operated as an insider dealing ring,” he said ”In relation to the six particular shares or stock lines, they collectively, through cheating, made a profit in excess of £1 million.”

He said the Mustafa brothers were “insider sources”, adding: “What each of them did was to get confidential information and pass it out to other defendants who could use it through spread betting and thus make a profit, having confidential information that was not known to the market.”