Former premier Tun Dr Mahathir Mohamad squashed rumour mills which cited that there is an ‘active underground’ urging Prime Minister Datuk Seri Najib Razak to step down.

"What we do know now is that I had openly called for his stepping down. No conspiracy. Just open declaration to the whole nation that I would like to see Najib cease to be Prime Minister.

"So if any investigation is to be made, there is no need for detectives or special agents. That there is a move or push for Dato Sri Najib to step down is known to everyone," he wrote in his latest entry in his blog, chedet.cc.

He said the call has been made public and there is no need for investigations on the alleged 'conspiracy'.

"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 said.

Apart from that, Dr Mahathir also criticised the comments made against the 1Malaysia Development Berhad (1MDB), saying that the standard answer is to deny, to say “No it is not true.”

"It is like somebody upon being asked whether he had stolen the money as alleged, simply denies that he had stolen, expecting the judge to acquit him simply because he denied," he said.

Meanwhile, Dr Mahathir also slammed certain people for saying that no one has any right to demand for Najib's resignation as Najib was an elected leader.

"How short is their memory. Don’t they remember Abdullah who was also elected being asked by Najib to step down. And he did. And I myself, also an elected PM, did step down in 2003.

"All over the world elected Presidents and Prime Ministers have been asked or forced to step down and they all did. In fact in some countries, if something untoward happens, Ministers, Prime Ministers step down," said Dr Mahathir.

The former premier has been Najib's fiercest critic over the 1MDB issue and the 1Malaysia People Aid (BR1M) in the last few months.

A Special Task Force from an independent committee and approved by Parliament has also been formed regarding the investigation towards 1MDB and the US$700 juta (RM2.65 bilion) worth of funds allegedly transferred to Najib's account.

The task force is headed by Attorney-General Tan Sri Abdul Gani Patail and aided by Inspector-General of Police, Tan Sri Khalid Abu Bakar, Malaysian Anti-Corruption Commission chairman Tan Sri Abu Kassim and Bank Negara Malaysia governor Tan Sri Zeti Akhtar Aziz.