KUALA LUMPUR, June 18 — 1Malaysia Development Bhd (1MDB) and owners Putrajaya must provide documentary “proof” to refute his allegations against the firm instead of issuing bald denials, Tun Dr Mahathir Mohamad said today.

In his latest riposte to 1MDB after the firm issued lengthy statements to question the motive of his attacks, the former prime minister told the state-owned company not to hide behind the veil of confidentiality to decline providing hard evidence.

“To all my criticisms 1MDB, can only say that they are all wrong. But there are no proofs given. The answer is always about secrecy of Government matters,” he wrote on his blog today.

Dr Mahathir also challenged 1MDB’s insistence that a Cabinet paper was prepared for a RM5 billion Islamic bond by the Terengganu Investment Authority, the firm’s predecessor, insisting that this document did not exist.

He added that the loan would have been incorporated into the federal government’s Budget if it is not another “off the books” deal, and pointed out that this was not the case.

“No Cabinet paper on the RM5 billion loan was presented. Produce the paper for the public to see. Of course you will say Cabinet papers are secret,” he wrote.

The former prime minister conceded to the firm’s correction of his claim that it was accruing RM3 billion in annual interest, but added that it made little difference as 1MDB still could not afford to service the RM2.4 billion actual figure.

He pointed out that 1MDB needed aid from tycoon T. Ananda Krishnan and Abu Dhabi’s International Petroleum Investment Company to meet its debt payments.

“Borrowing money to pay interest does not reduce the principal. It only increases the debt. Even if it is payment for shares or whatever, the loan would still be there.

“So you cannot explain more. It is confidential – secret,” he continued.

He further questioned the firm’s self description as a “strategic development firm”, pointing out that none of its announced projects have come to fruition.

Instead, he pointed out that the 1MDB’s main source of income was land that was sold to it by Putrajaya for a fraction of its market value, which Dr Mahathir said was no better rent-seekers selling APs, licences and contracts.

“Is 1MDB a strategic development company? What has it developed – nothing. Even Tun Razak Exchange is all fence and nothing else.”

Dr Mahathir has been at the forefront of attacks against 1MDB, a brainchild of Prime Minister Datuk Seri Najib Razak whose early resignation the former is now campaigning for.

The firm is currently under probe for alleged impropriety by at least three authorities, including the Auditor-General’s Department, Parliament’s Public Accounts Committee and Bank Negara Malaysia.