The MACC has served a notice to former prime minister Najib Abdul Razak summoning him to the graft-busters headquarters next Tuesday.

A MACC source said the summons is over the body's investigation into SRC International, a former 1MDB subsidiary.

Earlier today, eight MACC officers from its special operations division visited Najib at his house for an hour-long meeting.

Najib is accused of receiving RM42 million into his personal accounts from SRC International.

He had been questioned for two-and-half hours by the MACC on the matter in December 2015.

According to attorney-general Mohamed Apandi Ali - who has been directed to go on leave by Prime Minister Dr Mahathir Mohamad - Najib was unaware of the transfer of SRC International funds into his account.

Apandi had cleared Najib of any wrongdoing in the matter in January 2016.