Bersatu has formed a committee to scrutinise and vet membership applications from former Umno leaders, said its president Muhyiddin Yassin.
In a statement today, Muhyiddin said the committee will be chaired by his deputy, Mukhriz Mahathir.
"The committee will vet through the applications received to ensure the applicant is not involved in corruption, abuse of power, or crime.
"Bersatu will also work with the MACC and the police to conduct the vetting process. Besides that, political assessment will also be carried out internally," said Muhyiddin, who is also the home minister.
The party's central leadership will decide whether to accept or reject an application, after receiving a report from the committee, he added.
Muhyiddin's statement comes amid the exodus of MPs and assemblypersons from Umno. In the past two weeks, more than a dozen representatives have quit Umno and are either seeking to, or have already, joined Bersatu.
This includes former Malacca chief minister Rahim Thamby Chik, who was investigated for statutory rape of a minor in 1994, but later had the case dropped due to lack of evidence.
Finance Minister Lim Guan Eng, who was then the Kota Melaka MP, was jailed for criticising the then-government for not acting against Rahim.
Rahim had submitted his application to join Bersatu yesterday.
On Rahim's application, Muhyiddin stressed that it would be subjected to the same amount of scrutiny by the committee.
"At this stage, it is unfair to assume that any former Umno leader who applies to join Bersatu, will be automatically accepted.
"Their applications must be assessed first before the leadership can make any decision."