Putrajaya has refused to reveal how much the so-called Brazen Sky "units" are worth or reveal which institution is its custodian.

A parliamentary written reply on the matter by the Finance Ministry only states 1MDB's oft-repeated plan to repay its debts and made no mentioned of the Brazen Sky "units".

This is despite the question posed by DAP's Petaling Jaya Utara MP Tony Pua: "I urge the Finance Minister to state the value of the 'units' owned by 1MDB subsidiary Brazen Sky Ltd and the name of the institution which is the 'custodian' of the said units."

It is not clear what type of business Brazen Sky is involved in, but it remains a major part of the 1MDB saga and a key component of US Department of Justice investigations into 1MDB-related assets.

Coming under pressure from critics, 1MDB had in 2015 revealed that RM6.1 billion of the RM42 billion loaned by the company was channelled into Brazen Sky as "investment funds".

According to a press release by 1MDB in late 2015, the Brazen Sky "units" were originally valued at US$2.318 billion in September 2012 and were originally managed under a Cayman Islands-registered fund.

The "units", said the company, were the result of various equity and murabaha loan investments involving 1MDB's first joint-venture (JV) partner, London-based PetroSaudi International Ltd.

This deal involved US$1 billion investment by 1MDB, raised through government-bank bonds by 1MDB's predecessor, Terengganu Investment Authority (TIA). The JV was ratified on Sept 28, 2009, and terminated just six months later.

1MDB claimed that US$1.412 billion has been redeemed, but the complicated nature of 1MDB's books and the fact that there have been no financial statements since 2014, made the balance of the "units" difficult to determine.

Putrajaya, which wholly-owns 1MDB through Minister of Finance Inc, has also not been transparent on the financial institution which is currently managing the Brazen Sky "units".

Previously, Brazen Sky was supposed to be managed by BSI, but that bank was shut down in 2016 by the Singaporean authorities for money laundering and other misconducts.

In a statement today, Pua lashed at Prime Minister Najib Abdul Razak, who is also the finance minister, for refusing to answer his question and instead speaking about 1MDB's debt-repayment plans.

"He might as well have added that the sun rises from the East and sets in the West.

"The minister's answer could have been in less than 10 words, and it would have answered my question perfectly: Value of units, and name of the bank," said Pua.

He said his question to the finance minister was perfectly valid because 1MDB had stated publicly in April that the Brazen Sky "units" would be "monetised" to repay a debt to Abu Dhabi's International Petroleum Investment Company (IPIC).

A balance of US$602 million must be paid by Dec 31. The first tranche, due on June 31, was substantially delayed.

To learn more about Brazen Sky and its role in the 1MDB affair, please read our KiniGuides:

1MDB's debt payment plan and how it doesn't add up

The unmaking of 143-year-old bank BSI