Scandal-hit mining group says it seeks to recover the $152m in 2012 and $49m in 2011 that had 'no clear business purpose'

Bumi, the scandal-hit Indonesian coal miner, has revealed a $200m (£130m) black hole at its main subsidiary, as it released much-delayed financial results for 2012.

The FTSE-250 company – which has been dogged by a very public battle for control between financier Nat Rothschild and his co-founders, Indonesia's powerful Bakrie family – said it would seek to recover the money that had been spent over the past two years "with no clear business purpose".

A source close to Rothschild, who is no longer on the board but remains the company's second largest shareholder, said: "It's appalling but not surprising."

Bumi revealed the missing funds as it reported a pre-tax loss of $2.4bn for 2012, reflecting a decline in the value of its Indonesian mines, in part due to expectations of a lower coal price.

The company said that $152m in 2012 and $49m in 2011 had been wrongly attributed to the maintenance and extension of hauling roads, payments to landowners, consulting costs and goodwill.

It is working with the Serious Fraud Office and Indonesian authorities to track those funds down. Nick von Schirnding, who took over as chief executive of Bumi in January, said he had his suspicions over where the money ended up but would not be drawn on how confident he was of recovering it. "I would rather announce what we can once we've got the monies in the bank account. Rest assured I'm not going to leave any stone unturned."

The company has removed the chief executive and six other senior managers from Berau, the Borneo coal mine in which it has an 85% stake. It continues to search for a group finance director and chief mining officer to be based in Jakarta.

Bumi last month asked for its shares to be suspended amid the inquiry into irregular payments at Berau. On Friday it said it would apply for trading to resume once it had completed the process of improving internal controls, ahead of the annual meeting on 26 June.

Bumi was founded three years ago in a $3bn deal when the powerful Bakrie family placed its coal assets into a cash shell formed by Rothschild. But the two sides fell out amid accusations of financial irregularities – strongly denied by the family – and a whistleblower report, which the company alleged was based on hacked emails. In February this year, Rothschild failed in his attempt to gain control of Bumi, leaving the current management team in place.

Von Schirnding said: "I will now start building a reputation for doing the right thing. I believe that what we are doing here is ultimately all with one goal in mind: to make this company investable again."

Bumi is seeking to split from the Bakrie family with the sale of its stake in PT Bumi, Indonesia's biggest coal producer, for a cash sum of $278m. Von Schirnding said his preference would be to use this money "to reward long-suffering shareholders with a buyback or special dividend", although any decision on that would have to wait until at least the autumn.

The split from the Bakries would leave Bumi with its stake in Berau, which is due to produce about 23m tonnes of coal this year. Von Schirnding said the company would, in the future, look at buying other coal assets in Asia.

The review of Berau delayed Bumi's results by two months. On Friday, it reported revenues of $1.5bn for the year to 31 December, up 9% on the 10 months trading in 2011. The company sounded upbeat about the year ahead, noting that coal production in the first quarter of this year was 27% higher than the same period last year.

Von Schirnding said: "The first quarter results speak for themselves. During this whole mess the underlying business has performed very well.

The Bumi saga has captivated the City, particularly as Rothschild had worked furiously to become known as a serious financier and shed the playboy image of his university days, when he was famously a member of Oxford University's Bullingdon Club at the same time as the chancellor, George Osborne.