Malay Consultancy Council's (MPM) political and governance bureau head Datuk Seri Dr Mohd Hilmi Ismail said videos and photos showing several protesters assaulting police officers on the Internet were enough for the police and the relevant authorities to prosecute the organisers and others involved.
Hilmi also said the government's action against the organisers since its first rally in 2007 was "not satisfactory".
"Their leniency against the group has opened up the floodgates to more rallies which subsequently resulted in more violence.
"If we ignore this kind of behaviour, our country will be in chaos."
The rally saw violence break out after a group of protesters defied a court order and broke through the barricades leading to Dataran Merdeka.
As a result, some protesters and newsmen were allegedly assaulted by the police when the crowd was asked to disperse.
Home Minister Datuk Seri Hishammuddin Hussein had said the panel may be set up to investigate the alleged police brutality.
Meanwhile, MPM secretary-general Dr Hasan Mad called on Attorney-General Tan Sri Gani Patail and Inspector-General of Police Tan Sri Ismail Omar to take stern action against the organisers.
He said Datuk S. Ambiga, Datuk A. Samad Said and other opposition leaders should be held responsible for what had happened on that day.
"It is obligatory that they be prosecuted for the offences they have committed," Hasan said.
Former deputy inspector-general of police, who is also MPM security and well-being bureau head, Tan Sri Shamsuri Arshad, said the government should safeguard the country by protecting the silent majority.
"Those who have broken the law, action should be taken against them."
Shamsuri also said the organisers should compensate those who suffered damages and losses during the rally.
The Malaysian Human Rights Commission (Suhakam), meanwhile, has called on parties alleging human rights infringement to submit evidence and information to facilitate its probe.
Suhakam chairman Tan Sri Hasmy Agam said those wishing to do so can e-mail their information or complaints to firstname.lastname@example.org or email@example.com or call 03-26125600.