PKR Youth religious bureau chief Wan Ji Wan Hussin was arrested outside Sembilang Mosque in Seberang Jaya on Friday, by a team from Bukit Aman.
It is learnt that the arrest, around 2.45pm, was made after a police report was filed against him in Kuala Lumpur recently.
Wan Ji, who is also an Islamic preacher, was taken to the Central Seberang Prai police headquarters.
Penang police chief Comm Datuk Wira Chuah Ghee Lye confirmed the arrest and said that Wan Ji is being investigated under Section 4(1) of the Sedition Act.
On Sept 28, the 35-year-old was appointed by Lim Guan Eng as the Penang Chief Minister's information officer.
Wan Ji is a graduate of Al-Azhar University with a degree in Islamic studies.