PETALING JAYA (THE STAR/ASIA NEWS NETWORK) - Former Prime Minister Datuk Seri Najib Razak is due to face questioning in Putrajaya on Tuesday (May 22) over what he knew about funds transferred into his bank account from a unit of state fund 1Malaysia Development Bhd, which he founded.

Mr Najib is due to be escorted to the Malaysian Anti-Corruption Commission headquarters at 10am, an hour before new MACC chief commissioner Datuk Seri Mohd Shukri Abdull gives his maiden press conference as top graft-buster in the same building.

The anti-graft agency served Mr Najib notice on Friday to seek the former prime minister's cooperation over investigations into SRC International Sdn Bhd, a former subsidiary of 1MDB.

According to Reuters, the MACC is initially focusing on how RM42 million (S$14.2 million) went from SRC International to Mr Najib's account.

It is not known how many investigating officers will be involved or how long it will take but previous cases of questioning and investigations have gone up to 10 hours or more.

Like most people questioned by the MACC, Mr Najib is expected to be taken to the video interviewing room.

Three copies of the footage will be made, which will be kept by the witness, the investigating officer and the other to be submitted as evidence in court. This is to prevent any editing or manipulation of the videos.

It is learnt that only investigating officers will be involved in the questioning and no top MACC officer would be involved.

At 11am, Mr Mohd Shukri will hold a press conference where he has promised a "great story".

While he may be keen on talking about his life since his "retirement" in 2016, the media is expected to bombard Mr Mohd Shukri with questions about 1MDB, Mr Najib and whether the former premier would be spending the night there.

Mr Mohd Shukri served the MACC for 32 years before retiring at age 56 as the deputy chief commissioner (operation) at about the same time that former MACC chief commissioner Tan Sri Abu Kassim Mohamed "requested to have his contract terminated two years early".

In July 2015, he had said that there was basis for MACC to probe SRC International after looking at the issues surrounding investments by the energy company.

SRC International is an energy company owned by the Finance Ministry. It was a subsidiary of 1MDB until it was "de-merged" in February 2012.