UMNO Supreme Council member Datuk Seri Mohamed Nazri Abdul Aziz said former Prime Minister Tun Dr Mahathir Mohamad had willingly become the opposition's Trojan Horse.

He said this was because Dr Mahathir was willing to sacrifice his principles and to share the stage with the opposition when he realised that he was no longer welcome in any political party.

"He is a liability to all opposition parties. That is why he could not join any of the parties and had to form his own party," he told reporters at the Parliament lobby Monday.

Mohamed Nazri said Dr Mahathir was not only smart in playing his cards, but was also capable of changing the opposition's negative perception about him to ensure all his personal agenda would be accepted by the people.

"The people are not stupid to see his behavior and what he was doing. I'm sure they can judge it by themselves," he said.

Meanwhile, Pertubuhan Pembela Nasib Melayu Malaysia (Gerakan Merah) called for an investigation against Dr Mahathir and several other opposition leaders for allegedly issuing seditious speeches at the Bersih 5 rally here last Saturday.

Its president, Mohd Ali Baharom, better known as Ali Tinju, said the former prime minister and former Deputy Prime Minister Tan Sri Muhyiddin Yassin, Amanah president Mohamad Sabu and former Bersih chairperson Datuk S. Ambiga, had openly made speeches which incited people to topple the ruling government.

"They should be arrested and investigated as soon as possible," he told Bernama after lodging a report on the matter at the Pudu police station here Monday.

A total of 20 leaders and activists had been arrested since Friday in connection with Bersih 5 and Red Shirt rallies in the capital on Saturday.

The Malaysian Associated Indian Chambers of Commerce and Industry (MAICCI) president Tan Sri K. Kenneth Eswaran, on the other hand, urged Dr Mahathir Mohamad to stop interfering in the administration of the current government.

He said it was not right for the senior statesman to support the illegal Bersih rally after premiering the country for 22 years.

"Tun Dr Mahathir are riding on people for his own personal gain and grudge toward the current prime minister Datuk Seri Najib Tun Razak.--Bernama