Financier Nat Rothschild is 'completely, 100 per cent wrong' about the controversial deal that could end the feud at Indonesian mining firm Bumi, according to the firm's Deputy Chairman.

Rothschild resigned from the board of Bumi on Monday, saying he had lost confidence in the management's ability to stand up for investors.

In his resignation letter he accused the company's Chairman of being "complicit" in oppressing minority shareholders.

He said a it would be a "disgrace to proceed with, or even entertain" a deal laid out by the powerful Bakrie that could end a fierce boardroom rift and ongoing concerns over corporate governance.

However, Sir Julian Horn-Smith, Bumi's deputy chairman and senior independent director, told the Daily Telegraph that Rothschild was wrong to think the board was trying to do a deal before an investigation into "potential financial irregularities" at Bumi's Indonesian subsidiary, Bumi Resources, was completed.

"Nat's quite wrong about that. No decision has been made. We are looking at it systematically and carefully," he told the newspaper.

"The independent non-executive directors here are absolutely trying to do the right thing."

The Bakrie family has proposed swapping their stake in Bumi for a stake of equivalent value in Bumi Resources, thus ending the relationship between Bumi and themselves.

But rather than act as a peace deal, as some had expected, the offer led to Rothschild's resignation and further mud slinging.

The nature of his departure is subject to considerable speculation, with Rothschild's spokesman saying it was his decision alone.

However, there are also reports that Bumi Chairman, Samin Tan, had threatened to go if Rothschild didn't.

Accusations are now flying over the hacking of emails and telephones.

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