LONDON: A former Deutsche Bank managing director was sentenced to four and a half years in jail for insider dealing by a London court on Thursday, the longest prison term handed down in Britain for the crime to date.

After an unprecedented eight-and-a-half year investigation by the Financial Conduct Authority (FCA), Martyn Dodgson, 44, who advised the government during the global financial crisis, was jailed alongside his accountant friend Andrew Hind.

Hind, 56, a former finance director at fashion chain Top Shop, was sentenced to three and a half years after both were convicted on Monday for their part in a scam prosecutors said made more than $10 million from November 2006 to March 2010.

“This was persistent, prolonged and deliberate dishonest behavior,” Judge Jeffrey Pegden said.

The sentences draw a line under Operation Tabernula, an FCA investigation launched after two day traders brought attention to themselves in 2007 by attacking Scottish & Newcastle shares in what the FCA called “no holds barred, high-risk trading.”

Three years later, police raids and arrests linked to the investigation sent shockwaves through the City of London. The case culminated in three guilty pleas, followed by two convictions and three acquittals after a near four-month trial.

The FCA alleged Dodgson sourced inside information from within the banks where he worked, passed the tips onto middleman Hind, who then asked day traders to deal on his behalf. The men would split the profits, often using cash or payments in kind.

The two traders who first caught the FCA’s attention were Iraj Parvizi, an Iranian kebab shop worker turned multi-millionaire dubbed “Mad Punter” and Belgravia-based Scotsman Ben Anderson.