Allegations made about adultery show Prime Minister Najib Abdul Razak's camp can only rely on "sex stories" to defend the PM, Muhyiddin Yassin said today.

The Parti Pribumi Bersatu Malaysia (Bersatu) pro tem president said this in response to the Najib's press secretary, Tengku Sarifuddin Tengku Ahmad, who said Muhyiddin cannot be trusted because he was allegedly unfaithful to his wife.

This comes after Muhyiddin claimed former attorney-general Abdul Gani Patail showed him that Najib's bank account had RM1 billion, even before the RM2.6 billion "political donation".

"That (Tengku) Sarifuddin is bankrupt of ideas can clearly be seen from his vulgar allegations against me, raising nothing more than the usual sex stories that people of such base mindset are only capable of.

"That is how low Najib's yes man will go. A story popularised by a fugitive blogger has now become the main point used by Najib’s advisers and supporters to attack me," Muhyiddin said in a statement.

He was referring to blogger Raja Petra Kamaruddin, who had published a statutory declaration (SD) of the allegations.

In the SD, former deputy public prosecutor Stanley Clement Augustin claimed that his wife Nika Gee Siew Yee had a relationship with Muhyiddin since the latter's time as the Johor menteri besar.

Muhyiddin today reiterated that the "profanities" against him are untrue, and said the government should not distract the people from Najib's own scandals.

"Do not divert by raising fanciful conspiracy theories. Do not pretend that the country’s wealth has not been plundered. 

"Do not lie with Arabian night tales that the RM2.6 billion in Najib’s personal account was a donation by an Arab prince."

Najib had claimed the donation, made before the 2013 general election, came from a member of the Saudi royal family.

However, detractors cite reports by The Wall Street Journal, Sarawak Report and also the US Department of Justice's filings on 1MDB, to say that the money allegedly came from 1MDB instead.

Najib has denied such allegations, saying they are part of a plot to topple him.