New Delhi, Nov. 13 -- A Ukrainian anti-corruption agency said Tuesday it has detained five people and identified seven other suspects in a major graft investigation that is centering on alleged kickbacks worth some $100 million in the country's energy sector.

The National Anti-Corruption Bureau did not name the suspects in its statement but said they included a businessman believed to be the scheme's mastermind; a former advisor to the country's energy minister; and an executive of national atomic energy company Energoatom.

The statement came a day after the agency revealed some details of a 15-month investigation into suspected energy sector corruption, including at Energoatom.

Large amounts of Ukrainian and foreign funds have flowed ...