Bersatu president Muhyiddin Yassin says he has advised Johor Menteri Besar Osman Sapian over his move to appoint a private secretary who is allegedly an Umno member.

"I have told him not to be so hasty, and he has to be careful," Muhyiddin said, adding that Pakatan Harapan is under close scrutiny.

He said he has advised Osman to prioritise Bersatu members when making political appointments.

Muhyiddin was speaking to reporters when met at Anwar Ibrahim's home in Kuala Lumpur today.

Yesterday former Kota Tinggi district council president Fizwan Rashidi was seconded as Osman's private secretary.

When contacted by Malaysiakini, Fizwan confirmed his appointment as private secretary to Osman.

He, however, did not answer when pressed on whether he was still an Umno member.

"I am the state administrative officer (Johor Civil Service) serving the Johor menteri besar," was his brief reply to Malaysiakini in the form of a Whatsapp text.