Dyfed-Powys Police has arrested a 64-year-old man on suspicion of causing a public nuisance, in connection with five incidents at Pembroke Castle.

The arrest follows a series of incidents at Pembroke Castle in recent weeks, that saw areas of the castle cordoned off while investigations took place.

Superintendent Ross Evans said: “Police and other agencies have used significant resources responding to these five incidents over the past three weeks.

“We are treating them as linked.  On each occasion an unknown substance has been left in a container at Wogan’s Cavern, which is located behind the castle near the Mill Pond.

“We are waiting for forensic test results to confirm our hypothesis, but we are treating this as a series of hoax incidents.

“Hoax calls and incidents not only waste very valuable time for all emergency services, but also cause unnecessary concern within our communities.

“I would like thank members of the public and the management team at Pembroke Castle for their patience while we continue to investigate this matter.”

During the initial incident on July 13, A reporter at the scene was told a bottle bearing the word 'novichok' was found in nearby Wogan Cavern.

The latest report of an “unknown substance” found near Pembroke Castle on Monday was treated as a hoax.

Police cordoned off the footpath running beneath the castle at around 9am, with officers stationed at each end. The footpath re-opened a short while later, and Pembroke Castle remained open throughout.