Insiders in the Indonesian province of South Kalimantan, who chose to remain anonymous, told Bloomberg that the amount of coal stolen every three days was enough to fill a vessel the size of the Chrysler building.
Local industry groups estimate coal thefts across the Indonesian archipelago totalled $US6 billion ($A6.6 billion) last year.
The sources told Bloomberg that illicit mining at the Bumi Arutmin mine claimed 2 million tonnes of coal each month.
Those volumes are valued at about $150 million at current prices and are sidestepping a marketing contract with Glencore Xstrata, the world’s largest exporter of the fuel.
Asia Resource Minerals, which owns 29% of Bumi Arutmin, allegedly requested that law firm Macfarlanes assess the allegation of theft.
However, spokespeople for ARMS and Macfarlane issued no comment.
The claims have surfaced weeks before the Bakrie family is due to withdraw from the ARMS venture, with conflict between the family and investors cited as a factor.
Bakrie family spokesman Chris Fong said falling share prices were delaying the withdrawal.
Fong commented on the claims of theft in an email to Bloomberg, stating: “These accusations seem wild and extremely farfetched”.
“Mining operations in Indonesia are well regulated, documented and monitored across the entire chain of custody,” he added.
“There is no doubt that illegal activities surrounding the resource sector are well documented, however, we doubt at the scale as claimed.”
The Bakries are due to close the $501 million transaction on March 21.
The deal will see the family buying back the 29% stake in Bumi and regaining control of the operator of Arutmin.
Bumi stock has slumped 85% in Jakarta trading since 2012, while ARMS has slipped 75 % in the London Stock Exchange.
“The Indonesian Coal Mining Association estimates that 71 million tonnes of 2013 production can’t be tracked,” the group’s commercial committee chairman Pandu Sjahrir said.
At average benchmark Asian prices last year, that amount of coal would be valued at $6 billion.
ARMS CEO Nick von Schirnding has allegedly written to Jakarta-based Bumi seeking an explanation of the allegations.
