Toronto-based mining company Centerra Gold has said it has been made aware that its former President and CEO Leonard Homeniuk has been detained by the Bulgarian authorities, “apparently at the request of Kyrgyz Republic authorities”.

“The detention appears to be related to claims by the Kyrgyz Republic authorities of alleged improper transactions with Kyrgyz officials in connection with the restructuring of the Kumtor project in the 2003-2004 time period,” the gold miner said in a statement on its website.

Homeniuk, a Canadian citizen, was detained by Bulgarian authorities in Sofia on 27 July, Kyrgyz radio station Azattyk has reported, citing an announcement of Kyrgyzstan’s Interior Ministry.

Homeniuk was detained on an international arrest warrant issued in September 2014 by Kyrgyzstan’s prosecution authorities who are seeking his extradition on charges of corruption linked to contracts for the development of Kumtor gold mine, according to rus.azattyk.org.

Kumtor is the largest foreign-owned gold mine in the former Soviet Union. It accounts for about 12% of the economy of the Central Asian country and has been at the centre of heated debate between those favouring nationalization and officials who believe that would deter much-needed foreign investment.

Homeniuk served as Centerra Gold President and CEO from 2004 to 2008 and retired from the company in June 2008, according to the company statement.

Centerra also said it has not been advised of the reasons for the reported detention.

The gold miner recalled that it has “repeatedly publicly stated that it is not aware of any valid basis” for the allegations of improper transactions on part of Homeniuk relating to the restructuring of the Kumtor project. Meanwhile, the company had repeatedly requested information from Kyrgyz Republic authorities as to the factual basis for the allegations but no information had been provided.

“Centerra is deeply concerned about the detention of Mr. Homeniuk while on a family holiday, and supports his efforts to review the legality of his detention,” the statement read.

Centerra, whose operations have been plagued by protests and allegations of environmental damage, has been in tense negotiations with Kyrgyzstan since 2009, discussing a restructuring of the ownership of the Kumtor mine that would give the government a larger share of the proceeds, The Globe and Mail said in its coverage of the news of the detention of Homeniuk.