Human rights watchdog Hakam has joined the chorus of civil society movements that criticise police investigations against the organisers and participants of the anti-Zahid Hamidi rally on Saturday.

In a statement, its president M Ramachelvam, said such action was a harassment of peaceful protesters through systemic and procedural processes and this breaches their rights to a peaceful assembly as guaranteed under the Federal Constitution.

"There has been an established pattern by the successive governments to weaponise and utilise the Peaceful Assembly Act 2012 (PAA) to curtail public discourse, especially discourse which is against the ruling party of the day and its key leaders.

"The PAA creates cumbersome burdens on organisers and individuals in regard to public assembly.

"Hakam echoes and agrees with the various civil societies and the Bar Council on the harmful and detrimental effects of the PAA in subduing public participation and restricting the rights of the people," he said.

Ramachelvam added that actions by the authorities to suppress the right to freedom of assembly will hinder public participation and democratic engagement, which restricts public discourse and will weaken the nation.

"Hakam urges the government to respect the Federal Constitution and ensure safe and healthy public participation in a democratic society," he said.

The rally organised by Perikatan Nasional on Saturday was in protest against the government over a decision by prosecutors to withdraw corruption charges against Deputy Prime Minister Ahmad Zahid Hamidi.

Called the 'Save Malaysia' rally, protesters first gathered at the Masjid Jamek Kampung Baru in the heart of Kuala Lumpur for prayers before PN activists Badrul Hisham Shaharin, popularly known as Chegubard, and Tun Faisal Ismail Aziz led them on a march to the Sogo shopping complex, where speeches were delivered.

Deputy Inspector-General of Police Ayob Khan Mydin Pitchay has since announced that police are investigating 25 individuals over the rally, which he said did not comply with PAA for lack of notice, and also for being held at a mosque - a prohibited place for rallies under the law.