The police have opened three investigation papers on complaints lodged against former Prime Minister Tun Dr Mahathir Mohamad, Deputy Prime Minister Datuk Seri Dr Ahmad Zahid Hamidi said today.

Ahmad Zahid, who is also the home minister, said two of the papers were related to ongoing investigations while one had been referred to the Attorney-General's Chambers for further instructions.

"The police opened two investigation papers on complaints lodged against Tun Dr Mahathir Mohamad, based on Klang Report 33074/14, and investigations were being conducted under Section 500 of the Penal Code for defamation.

"The investigation papers will be referred to the Deputy Public Prosecutor for comment and further instruction after the investigations have been completed," he said in a written reply in the Dewan Rakyat.

Ahmad Zahid gave the reply in response to a question from Tan Kok Wai (DAP-Cheras) who had asked him to state the outcome of investigations and the action taken against Dr Mahathir.

The deputy prime minister said that another investigation paper, based on Jinjang Report 18448/2015 under Section 500 of the Penal Code, was referred to the Attorney-General's Chambers on Oct 9 for further instruction.