A group of youths were spotted entering the abandoned grounds of the former Rhu Bowling Club, say police.
Officers were alerted to the group "causing a nuisance" on the site at Inchgower Grove on Monday, February 19.
A police spokesperson said: “This would appear to be an ongoing issue, however no youths were traced upon police arrival.”
The bowling club, which was established in 1909, closed down in 2013 and the site has remained vacant ever since.
A planning application to build houses on the land was refused by Argyll and Bute Council the following year.
The Helensburgh and District Men's Shed group had hoped the site might provide them with a permanent home, but efforts to secure a lease for the site fell through in 2021.
A demolition order for the pavilion at the site was submitted to the council in November of that year.
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