The police have detained a man who allegedly insulted the Johor Royal Institution recently, via Facebook.

Johor police chief Datuk Wan Ahmad Najmuddin Mohd said the 37-year-old suspect was picked up at his house in Larkin Jaya here about 3.30am yesterday, following a police report on Dec 7.

"The words used by the man (via Facebook) were very insulting to our Royal Institution and this matter cannot be allowed," he told reporters here today.

Wan Ahmad Najmuddin said a cellphone was also seized from the man whose urine tested negative for drugs, adding that he had a record for criminal intimidation in October.

He said the man was remanded for four days and would be investigated under Section 4 (1) of the Sedition Act 1984.