A creditor has initiated bankruptcy proceedings at a Jakarta court against a unit of Indonesian coal miner PT Berau Coal Energy Tbk over alleged unpaid debts.

PT Cakra Sinergi Investama, which had started the court proceedings, has claimed that Berau Coal Energy's unit, PT Berau Coal, owes it money, Berau Coal Energy said in a filing to the Jakarta stock exchange, without disclosing the amount.

Berau Coal had originally owed the money to PT Fortuna Star, but Fortuna Star had transferred this debt to Cakra Sinergi, according to the filing.

Berau Coal is "making checks and verifications in a detailed and in-depth manner", Berau Coal Energy said.

Indonesian conglomerate Sinar Mas Group is in talks with bondholders to restructure $950 million worth of debt held by Berau, which it is in the process of acquiring, its executive said earlier in July.

A Singapore court had imposed a moratorium on debt issued by a unit of Berau Coal Energy, giving it until Jan. 4 to negotiate with bondholders.