A group of investors, including director Mick Geoghegan and his brother Brian, husband of health minister Mary Harney, have all but completed a €3m fund raising to test a huge gas-from-coal prospect that lies just eight miles off the Dublin City coast.

The Kish Basin prospect, close to the lighthouse of the same name, is said to hold up to 2bn tonnes of "clean" gas-from-coal energy that could power scores of power stations for many years.

VP Power, which has held an exploration license across large sections of the Kish Basin for the last two years, is led by the Dun Laoghaire marina developer Michael O'Leary (no relation to Ryanair CEO), and chairman Con Casey, managing partner of accountants LHM Casey McGrath.

Between them, geologist Mick Geoghegan, a senior director of VP Power, and Brian Geoghegan, as an investor, hold "a slice" of the shareholding in the company, O'Leary said. "All the seismic information off the ship is now in two universities and with a specialist house to analyse these reports." Raglan Capital is leading the investment round to complete the second stage seismic study.

VP Power said it will use the new funding to prove the quantity and quality of the coal in the 26 seams in the Kish prospect. Clean technology, called underground coal gassification, that heats the coal in the underwater rock reservoirs to extract gas, has been proven in other parts of the world, say the investors. The costs, though still considerable, would be lower and cleaner than extracting energy from oil sands in Canada, VP Power says.