National security police on Monday arrested a man on suspicion of posting messages on social media with seditious intent.
The suspect, 46, was detained in Hung Hom.
Officers searched his home with a court warrant and seized electronic communication devices.
Police accused the man of repeatedly publishing posts inciting hatred towards the central and SAR governments, calling for sanctions against officials and inciting the use of violence.
Officers said performing acts with seditious intent is a serious offence, with a maximum penalty of two years in jail on the first conviction under the Crimes Ordinance.