A Mongolian investigation into allegations of corrupt mining payments has ensnared a former prime minister who has been asked to return from the US to answer prosecutors’ questions.

Saikhanbileg Chimed, prime minister for two years until 2016, is the highest-ranking official to have been implicated in the probe, which dates from revelations in the leaked Panama Papers of transfers to a Swiss bank account in the name of Bayartsogt Sangajav, the former Mongolian finance minister. Swiss authorities froze the account in January.

Over the weekend, Mongolian authorities arrested Mr Bayartsogt and two other former officials with ties to Erdenes Mongol, the state-owned holding company set up to contain Mongolia’s shares in mining projects including the Oyu Tolgoi copper mine and the Tavan Tolgoi coking coal deposit. They also requested Mr Saikhanbileg return from the US. Mr Saikhanbileg could not be contacted for comment.

Turquoise Hill, the Canada-listed subsidiary of Rio Tinto which is developing a $5bn underground stage of the Oyu Tolgoi mine, has previously said it received a request for more information by the Mongolian anti-corruption authorities.

The request for information concerned the “possible abuse of power by authorised officials” during the negotiation of the 2009 Oyu Tolgoi investment agreement, shortly after Rio took over negotiation of the Oyu Tolgoi project from Ivanhoe Mines, the original developer.

Mr Saikhanbileg signed the agreement to develop the second, underground phase of the mine, which economists said was necessary for the Mongolian government to meet its budgetary commitments. Negotiations over the first phase of the giant mine were also fraught, with rancour on both sides and repeated changes to Mongolia’s mining investment regime, once the most liberal in the world.

Swiss prosecutors have said the investigation was not directed against Rio or its employees. Rio Tinto declined to comment on Tuesday.

“The Mongolian government and public is slowly beginning to build up capacity to analyse its relationship with Oyu Tolgoi and with Rio Tinto as an investor and to ask questions about that relationship in the process,” said Julian Dierkes, an expert on Mongolian civil society at the University of British Columbia.

Mr Saikhanbileg’s departure from office in 2016 was marred by the contentious $400m purchase of nearly half of the giant Erdenet copper mine in Mongolia’s north from Russian holding company Rostec, which returned the entire mine to Mongolian ownership.

Erdenet long had symbolic value as the Soviet Union’s most important investment in Mongolia but has been plagued by allegations of mismanagement and corruption. The previously unknown private company that bought the stake, Mongolian Copper Corp, is fighting the Mongolian government’s decision in February 2017 to nationalise the stake bought from Rostec.

Bayanjargal Byambasaikhan, former chief executive of Erdenes Mongol, told the Financial Times in 2016 that the holding company would have trouble establishing control over the state’s share in Erdenet due to the complexity of the politics surrounding that mine. Mr Byambasaikhan was one of the people arrested this weekend.

In a statement on Tuesday, the Business Council of Mongolia, an organisation chaired by Mr Byambasaikhan, noted that he had returned to Mongolia from a posting at the Asian Development Bank in 2010, after the 2009 investment accord for the Oyu Tolgoi mine. “The BCM Executive Committee has full confidence in Byambasaikhan’s integrity,” it said.

Published Date:2018-04-04