Police are expected to wrap-up soon their investigations against Dr Mahathir Mohamad for his remarks on the sidelines of the Bersih 4 rally in August.

Inspector-general of police Khalid Abu Bakar said discussions are under way with the Attorney-General's Chambers and would be completed soon.

"We are updating ( kemaskini ) the investigation papers and it discussing with the attorney-general. It will be done soon," Khalid told a press conference in Kuala Lumpur today.

Several police reports were filed against Mahathir after he accused Umno grassroots leaders of taking bribes.

Last month, the police recorded a statement from the former prime minister on this matter.

Mahathir told reporters then that he did not answer the questions posed to him by the police officers.

He is on a campaign to oust Prime Minister Najib Abdul Razak, who he claims committed a slew of misdeeds in connection with 1MDB and the RM2.6 billion political donation.

However, Najib has denied any wrongdoing and claimed the allegations are a part of conspiracy to topple him.

Mahathir's double appearance at Bersih 4 raised eyebrows as the former prime minister is known oppose street rallies and clamped down on such demonstrations during his tenure.

Recently, Mahathir also said Najib should be arrested under the Special Offences (Special Measures) Act 2012, apart from accusing the latter of attempting to bribe him.

Last week, Home Minister Ahmad Zahid Hamidi said he would discuss with Khalid to determine if this statement warranted an investigation as well.