IT IS inevitable that energy companies will one day tap the last frontier, Antarctica, an energy expert says.

Ali Samsam Bakhtiari, of the University of Tehran, said the peak of oil supply from known reserves had been reached and "the day [the companies] decide, they will go in".

In Hobart yesterday, Dr Bakhtiari told a conference of the Scientific Committee on Antarctic Research that more than half of the world's 1900 billion known barrels of oil had been used, leaving more difficult and expensive reserves.