Two young men were caught red-handed by fellow beachgoers spraying graffiti on the rocks at St Peter’s Pool on Sunday afternoon.
A video was sent to Times of Malta showing two men spray-painting the rocks of the popular and busy bay.
The person who shot the footage at 2pm told Times of Malta they had called the police but no officers had turned up an hour later.
They added they had raised the alarm over the vandalism as beachgoers should "enjoy the island but not disrespect it".
When contacted, the police said they had turned up on site, found one of the alleged sprayers and accompanied him to the Birżebbuġa police station for questioning.
A spokesperson said the police received the report at 2pm and arrived at the site shortly after at 2.30pm.