He arrived at the federal police headquarters here at 10.03am, dressed in a white shirt, beige coat and songkok.

Criminal Investigation Department chief Huzir Mohamed had said Zainal would be investigated based on a police report lodged by an aide to P Ramasamy, the Penang deputy chief minister.

He said the case would be investigated under Section 504 of the Penal Code for intentional insult, and Section 233 of the Communications and Multimedia Act for use of network facilities to annoy, abuse, threaten or harass others.

In his speech at the congress, Zainal said the non-Malays were bound by a social contract with the Malays, and warned them that their citizenship could be suspended if they break the agreement. He also said that Malaysia belongs to the Malays.