His surprise application filed on Monday said he had "clear information" that then-king Sultan Abdullah Sultan Ahmad Shah issued an order during the January 29 pardon's board meeting, which cut his 12-year jail sentence by half and sharply reduced a fine, allowing him to finish his sentence under house arrest.
Najib asked the court to have the government verify and carry out the order.
His application was due to be heard on Thursday but was postponed to April 17.
Sultan Abdullah hails from Najib's hometown of Pahang.
He ended his five-year reign on January 30 under Malaysia's unique rotating monarchy system.
A new king took office on January 31.
Najib, 70, has served less than two years of his sentence, supposed to end on August 23, 2028, after his sentence was commuted.
He was charged and found guilty in a corruption case linked to the multibillion-dollar looting of state fund 1MDB.
In his application, he accused the pardons board, home minister and the attorney-general among seven entities of concealing the sultan's order "in bad faith".
Home Minister Saifuddin Nasution Ismail told reporters later Thursday he had "no knowledge" of such an order, adding that he was not a member of the pardons board.
The others named in the application could not be immediately reached for comment.
Najib set up the 1MDB development fund shortly after he took office in 2009.
Investigators allege at least $US4.5 billion ($A6.9 billion) was stolen from the fund and laundered by Najib's associates through layers of bank accounts in the US and other countries and financed Hollywood films and extravagant purchases that included hotels, a luxury yacht, art and jewellery.
More than $US700 million landed in Najib's bank accounts.
The national outrage over the scandal led to the shocking 2018 election defeat of the party that had governed Malaysia since independence.
Najib was sentenced in 2020 and two years later, he lost his final appeal in court, becoming the country's first former premier to be imprisoned.
Despite his conviction, Najib still holds clout in his party, the United Malays National Organisation, which is part of Prime Minister Anwar Ibrahim's unity government that took power after the 2022 elections.
Najib has maintained his innocence, alleging Malaysian financier Low Taek Jho duped him.
Low, thought to be the mastermind of the scandal, remains at large.
The former premier's separate graft trial over the 1MDB scandal is ongoing.
