The jewellery stolen from the museum was art nouveau

Brighton Council confirmed there had been two breaches of security at the Royal Pavilion Estate in two months.

A silver serving dish was taken in a raid in June. In a second raid last week, three art nouveau jewellery pieces were taken from a locked drawer.

The GMB union said job cuts had led to security concerns among museum staff.

"Improvements to security in the Royal Pavilion have already been undertaken in light of the first theft," a council statement said.

STOLEN MUSEUM ARTEFACTS French hair ornament set with diamonds, c 1900 Another French hair ornament designed as a dragonfly, c 1900 Gold pendant designed as a spray of snowdrops set with two child baby teeth, c 1900 A silver serving dish, c 1807

It said detailed security risk assessments were looking at "all aspects of security" including the buildings, collections, visitors, staff, and CCTV.

"The importance of these assessments cannot be underestimated in the light of this latest incident," it added.

But the public sector GMB union said it had been raising concerns about staffing, safety, and security "for months".

Spokesman Mark Turner said eight job cuts that saw the department reduced to 28 workers led to worries about "the safety of our staff and protecting the city's crown jewels".

Solid silver

He said the GMB was considering balloting for strike action.

"We will be looking at registering a dispute with the council," he said.

"We have told them that we want more staff because staff levels are not right, particularly at locking up times."

Police said the solid silver dish valued at several thousand pounds was noticed missing from a public area on 4 June.

And on 17 August, a security guard noticed the jewellery items were missing and called police.