Former prime minister Dr Mahathir Mohamad has once again called on Prime Minister Najib Abdul Razak to resign, this time for his "stupid move" to sign documents without reading them.

This, Mahathir said, was based on the findings of the Public Accounts Committee (PAC) report on 1MDB, which shows how Najib is required to authorise all major decisions made by the state-owned fund.

"How do we authorise a document? By signing it. When we put our signature on a document, we authorise it...