In what the FSA claims is the “largest-ever operation against insider dealing,” 143 agents from the watchdog led a swoop on 16 addresses in London, the South East and Oxfordshire in the early hours of Tuesday morning.

For extra theatrical flair, the venture was assisted by the Serious Organised Crime Agency (Soac), in their first project with the FSA.

According to the regulator, six men have now been arrested, including “two senior City professionals at leading city institutions and one City professional at a hedge fund” who are alleged to be immersed in “a sophisticated and long-running insider-dealing ring”.

The banks involved in the probe are said to include Moore Capital, Exane and Deutsche Bank.

With the Conservatives pledging to abolish the FSA should they win the next election, and recent criticism that the regulator had scant evidence that it was maximizing its new powers to clean up the City, the FSA is no doubt thrilled with the scale of its latest project.

Although the FSA declined to release any further details about the case, no doubt we can expect more drama to trickle out from the regulator as the case unfolds.

According to Simon Morris of law firm CMS Cameron McKenna: “The FSA is striking to maintain the good name of the City [but] the proof of the striking is in the jailing, and we will have to wait several years before we know whether the FSA has found a smoking gun or a damp squib.”