“The company announces that Professor Christopher Green has stood down from the board of Regal Petroleum plc. Professor Green feels that he is unable to dedicate the time required of an executive member of the board. The company will continue to seek an alternative candidate for this position,” said a Regal statement to the London Stock Exchange on Tuesday.

Last week £220 million was wiped off the market value of Regal Petroleum after its share price collapsed following the disclosure that one of the firm’s key wells was "uncommercial".

In early March Regal was trading over £5.00 but has been savaged recently on disappointing drilling results, trading this week as low as 84p. It dropped from £2.55 to £1.00 in one day after the Kallirachi-2 well results were announced. Last night it closed at 91p.

The other recent board addition, Dr. Rex Gaisford, also made an executive time as the same time as Green, confirmed his commitment to the board as director of production, the company said.