KUALA LUMPUR (THE STAR/ASIA NEWS NETWORK) - It was a quiet Wednesday (May 23) morning in Langgak Duta as only a handful of reporters were still camped out in front of the residence of former Malaysian prime minister Najib Razak.

A convoy of three vehicles, including Datuk Seri Najib's white Toyota MPV, was seen leaving the residence at 9.50am.

It is not yet known where he was headed.

On Tuesday, Mr Najib was questioned by the Malaysian Anti-Corruption Commission (MACC) for several hours over the probe into SRC International, a former subsidiary of the controversial 1Malaysia Development Berhad (1MDB).

The former premier briefly told the media that was waiting outside the MACC headquarters that he would have to return on Thursday for further questioning.

Mr Najib, who wore a blue blazer, said his statement on SRC was a continuation of what he gave to MACC in 2015.

"My statement is a continuation of that, with verified documents and details as required by the MACC," he said.

The former prime minister thanked the officers who questioned him for their professionalism.

Mr Najib revealed that he was questioned from 10am to 2.15pm, with a 30-minute break in between.

The anti-graft agency served the former premier notice last Friday to seek his cooperation over the investigations.

Najib has consistently denied any wrongdoing related to 1MDB since the scandal erupted in 2015, but he replaced an attorney-general and several MACC officers allegedly to shut down an investigation.

Najib has said the RM2.6 billion (S$877 million) of funds deposited in his personal bank account were a donation from a Saudi royal, rebutting reports that it came from 1MDB.

The MACC has reopened its investigation, initially focusing on how RM42 million went from SRC International to Mr Najib's account.

SRC was created in 2011 by the Najib administration to pursue overseas investments in energy resources, and was a unit of 1MDB until it was moved to the Finance Ministry in 2012.