ULAANBAATAR, June 13 (Reuters) - A former Mongolian finance minister and a businessman held since April as part of an investigation into negotiations on the Oyu Tolgoi copper and gold mine operated by Rio Tinto have been released, court sources said.
The prosecutor's office requested their release on Tuesday. Both former officials are prohibited from travelling abroad.
Former finance minister Bayartsogt Sangajav was arrested with Byambasaikhan Bayanjargal, former chief executive of state-owned investment company Erdenes Mongol.
Mongolia's Independent Agency Against Corruption is investigating suspected misuse of power in connection with a 2009 agreement to develop the Oyu Tolgoi mine.
It was signed by the government with Rio Tinto and Canada's Ivanhoe Mines (now called Turquoise Hill Resources Ltd) and was followed by a 2015 deal to expand the project.
Bayartsogt's lawyer said he expected his client to be acquitted.
Bayartsogt is keen to cooperate with investigators and had voluntarily come to the country to "establish the truth", the lawyer told media in Mongolia.
Former prime ministers Bayar Sanj and Saikhanbileg Chimed were also arrested as part of the investigation.
The Independent Agency Against Corruption was not available for immediate comment. (Reporting by Munkhchimeg Davaasharav; writing by Barbara Lewis; editing by Jason Neely)