On June 23 the company announced that Doran had been struck by a sudden illness and that chief operating officer Bruce Clements had been appointed acting chief executive.

Doran, a veteran of the petroleum industry with more than 30 years of experience under his belt, has led Roc since its foundation in 1997.

Roc chairman Andrew Love said in a statement that Doran's sensibly contrary enthusiasm, passion and charm had been the company's driving force, and he would be greatly missed by its board, staff, business partners and shareholders.