The former boss of Sibir Energy was fined £350,000 yesterday for failing to disclose substantial cash payments to its biggest shareholder.
The penalty – one of the largest so far levied on an individual – brings the curtain down on one of the biggest scandals to hit the London Stock Exchange's Alternative Investment Market (AIM).
The Financial Services Authority sharply criticised Henry Cameron's conduct, saying that in two separate market announcements made by Sibir – then AIM's largest company – in December 2008 and February 2009, incorrect figures were given for the payments Sibir had made to Chalva Tchigirinski, a Russian tycoon.
The announcements claimed that Sibir had paid a total of $115.4m (£76m) when in fact the true amount was more than $300m. They also stated that the payments were advances for real estate that Sibir was to purchase from Mr Tchigirinski. In fact, the FSA said they were not supported by a written agreement and amounted to unsecured loans. This, the FSA said, created a false market in Sibir shares.
The watchdog found that the primary motive behind Mr Cameron's conduct was to retain Mr Tchigirinski's supportive shareholding in Sibir and to prevent him from having to sell up as a result of financial difficulties.
When the true position became clear, Sibir's shares were suspended and ultimately its listing was cancelled, although shareholders did not lose after it was taken over by the Russian energy group Gazprom Neft.
The FSA, in its final decision notice, said personal gain was not Mr Cameron's motivation and he was in fact attempting to preserve Mr Tchigirinski's supportive shareholding in Sibir to avoid the consequences of a forced sale of Mr Tchigirinski's stake.
But in a strongly worded statement, the FSA's director of enforcement, Margaret Cole, said: "As the most senior executive director at Sibir, Cameron should have known these announcements were misleading and the serious impact they were likely to have on the market. Our fine reflects the gravity of his irresponsible actions and shows that we are serious about taking action against directors of publicly traded companies who commit market abuse."
Significantly, the company and Mr Cameron's colleagues escaped any censure, with the watchdog laying the blame firmly at his door. Had he not settled early, the fine would have been £500,00.
In a statement, Mr Cameron said: "The agreement that I have reached with the FSA and my acceptance, without an admission on my part of liability, of the penalty that [it has] imposed has been reached solely because of the very heavy burden of defending myself. If I had continued the total legal costs would have been many times in excess of the agreement I have reached."
Sibir Energy's most recently published annual report showed that Mr Cameron was paid £2.451m in 2007 and £3m in 2006. Mr Tchigirinski was not accused of any wrongdoing.