Following his appointment as deputy home minister, Nur Jazlan Mohamed said he would have to relinquish his position as Public Accounts Committee (PAC) chief.
He also revealed the committee's hearings concerning 1MDB in August will have to be postponed.
This follows the appointment of four PAC members as cabinet minister or deputy ministers.
The other three BN MPs are Reezal Merican Naina Merican, Mas Ermieyati Samsudin and Wilfred Madius Tangau.
"All proceedings that had been arranged for August, including 1MDB will be halted until the new PAC line-up is announced at the next Dewan Rakyat sitting," he was reported as saying.
The next sitting would only take place in October.
PAC was scheduled to hear evidence from 1MDB president Arul Kanda, former 1MDB CEOs Shahrol Azral Ibrahim Halmi and Mohd Hazem Abdul Rahman next week.
Then in mid-August, PAC was supposed to interview two 1MDB directors - Mohd Bakke Salleh and Azlan Mohd Zainol - who quit in 2009.
PAC has also summoned business tycoon Jho Low through the Finance Ministry.
Parliament's Standing Orders allow for the hearing to continue if the PAC quorum of three is met. Thus, the meeting can continue in Nur Jazlan's absence.
With Nur Jazlan's statement, it is uncertain if the witnesses would still recognise the legitimacy of the PAC and turn up.
Cabinet had ordered the PAC to investigate the 1MDB controversy, alongside the audit by the National Audit Department.
There has been criticisms that the decision to appoint the four BN MPs to cabinet was an attempt to stymie PAC's probe on 1MDB.
Among others, Baru Baru MP Sim Tze Tzin has urged the four BN MPs in the PAC to refuse their cabinet appointments until the 1MDB probe is complete.
"The appointment of these four PAC members are sudden and raise the question whether it is a 'coincidence' to frustrate the current investigation or attempt to co-op the members of PAC
"We urge the four BN PAC members to stand up for the rakyat to search for the truth first. They can join the cabinet later," said Sim.
Malaysiakini has attempted to contact Nur Jazlan numerous times to get his comments.