There is no need to investigate allegations of a conspiracy to oust Prime Minister Najib Abdul Razak, said Dr Mahathir Mohamad.
Dismissing the existence of a cloak and dagger plot, he said: "There is no need for detectives or special agents. That there is a move or push for Najib to step down is known to everyone."
"Is there a conspiracy? Is there someone or some group conspiring i.e moving in secret in the underground to overthrow Najib.
"There could have been before but apart from people complaining privately about their dissatisfaction with his administration, no one was planning his overthrow.
"That is not to say they did welcome the idea of his resigning or vacating his post. But active underground planning and action there was none," he added in his blog.
Mahathir said he has openly called for Najib to resign, and hence there is no conspiracy on his part.
"Just open declaration to the whole nation that I would like to see Najib cease to be prime minister.
"So again where is the conspiracy! It is all in the open. There is no need to conspire. There is open campaigning for his ceasing to be prime minister," he added.
Since April, Mahathir has been firing a series of salvos against Najib and 1MDB, warning that BN would lose the next general election if he remained as prime minister.
Following a report in The Wall Street Journal claiming that RM2.6 billion was deposited into the prime minister’s personal bank accounts, Najib blamed Mahathir as the mastermind.
The government has also claimed that tampered documents had been used to smear the prime minister.