The allegations revolve around the sale of share options by directors after they received, then shelved, an internal plan forecasting poor results.
The total profit made by the six is said to be pounds 3,564,634, with shares worth an additional pounds 1,251,715 still uncashed.
City experts last night said that their actions might not be deemed insider trading, since the report they saw was never intended to be made public.
Insider deals usually revolve around sales made before public announcements which adversely affect share prices. The company also disputed elements of the allegations.
However, the claims will heighten the political row over privatised utilities.The Shadow Chancellor, Gordon Brown, described it as "the worst example yet of share option practice".
A spokesman for the Serious Fraud Office said in a statement: "Allegations relating to PowerGen made to a journalist have been passed to the director of the SFO by the Metropolitan Police. As happens routinely, the director will decide whether or not it would be appropriate to investigate.
"He wishes to stress that this should not be interpreted as being the start of an SFO investigation." The Stock Exchange's surveillance unit is also said to be examining the claims.
The fresh claims about PowerGen, in today's Observer, were disputed last night by Sir Colin Southgate, non-executive director of PowerGen, who released a letter which said that when the share options were exercised, "profits for 1993/94 and the board's view of profit performance for 1994/95 were in line with market expectations''.
He added: "The market had all the relevant information at the time the options were exercised. The board was confident that the company would meet market expectations and it has."
Sir Colin disputes quotes attributed to him by the Observer describing the profit predictions in the plans rejected by the board as "the lowest we had ever seen in PowerGen". He also denied saying he had urged the directors not to sell their share options. The Observer says that it has shorthand notes and a tape recording of the interview.Reuse content