Prime Minister Najib Abdul Razak has fired a salvo at his former mentor turned nemesis Dr Mahathir Mohamad and other critics of 1MDB without mentioning names.

Speaking at a mosque in Putrajaya after presenting offer letters to 1,100 individuals to perform the haj with 1MDB funds, the prime minister touched on the criticism towards the firm, whose transactions have become the subject of various international investigations and court action.