Malaysia's police have denied being controlled behind the scenes, as a rift grows between cops and graftbusters over the investigation of leaks in the 1Malaysia Development Berhad (1MDB) scandal.

Police chief Khalid Abu Bakar yesterday dismissed talk that the police are taking instructions from others or interfering with the work of the Malaysian Anti-Corruption Commission (MACC), following recent police raids on MACC offices.

"(The police are) clear on the direction of our investigation on the case, where official government and banking documents were leaked and manipulated by certain parties to upset the stability of the country," he said in a statement.

MACC officers have been questioned in the course of police investigations into the alleged leaks, which have led to damaging media exposes against troubled state investor 1MDB and its chief adviser, Prime Minister Najib Razak.

Senior MACC officials have insinuated that the police were acting on instructions of someone higher up. But Tan Sri Khalid said: "The public must understand that each government agency has its own duty and responsibility in an investigation." He said that the police probes are "still in line with the original purpose, which is to find the truth".

The pressure on MACC led to the unlikely sight of Malaysia's top opposition leaders - so often at loggerheads with the agency in the past - turning up at its Putrajaya office yesterday to show support.

"This situation of police harassing MACC must stop," said Democratic Action Party adviser Lim Kit Siang, after meeting MACC spokesman Rohaizad Yaakob.

The ruling Barisan Nasional coalition's Youth chief Khairy Jamaluddin supported the MACC's recent statement that it would question Datuk Seri Najib on a US$700 million (S$960 million) donation banked into his personal bank accounts. He said yesterday the probe must continue until "the results of the investigations convince the people".

Separately, Tan Sri Vincent Tan has denied allegations published in a blog supportive of Mr Najib's Umno party that he donated RM400 million (S$143 million) to opposition parties at the 2013 General Election. The blog accused former premier Mahathir Mohamad of criticising the donation that Mr Najib received while ignoring those of the tycoon, who is seen as close to Tun Dr Mahathir.

"It is obvious that the allegations are purely a figment of the writer's imagination," Mr Tan said.

Teo Cheng Wee