1Malaysia Development Bhd (1MDB) said it is committed to continuing to provide responses to former Prime Minister Tun Dr Mahathir Mohamad to help the latter remember its fact-based answers.

In a statement today, 1MDB said Dr Mahathir "continues to reuse and recycle stale and unproven allegations, which have repeatedly been proven wrong."

"For example, Tun Mahathir previously claimed that RM42 billion was missing from 1MDB. Now, he claims that 'over RM 20 billion cannot be traced or accounted for'.

"For Tun Mahathir's benefit, a comprehensive breakdown of how 1MDB utilised its RM42 billion of debt -- based on the company's audited financial statements -- can be found at http://1mdb.com.my/press-release/rm42-billion-all-accounted-for," it added.

The statement was issued by 1MDB following certain statements relating to the state investment fund posted by the veteran former politician in his blog on Sept 25.

"In relation to 1MDB land, Tun Mahathir conveniently forgets that 1MDB is 100 percent owned by the Malaysian government and therefore, any land value increase directly and solely benefits the government.

"Apart from now quoting a much lower land value of RM3,000 per square foot (vs RM7,000 per square foot in a previous allegation by him), Tun Mahathir forgets to acknowledge that 1MDB has committed RM3 billion on infrastructure development in TRX.

"This equates to approximately RM1,500 of infrastructure expenditure per square foot, paid for by 1MDB, and subsequently recovered through land sales," said 1MDB.

It added that Dr Mahathir had also repeated his old claim that 1MDB transferred funds to the private accounts of Prime Minister Datuk Seri Najib Razak.

"As he will be well aware, this is despite the independent Malaysian Anti-Corruption Commission (MACC) clearly confirming on Aug 3, 2015 that the funds were from a private donor and not from 1MDB.

"1MDB regrets that Tun Mahathir keeps forgetting the facts, not just from 1MDB but from independent and respected agencies such as the MACC," said 1MDB.