Saudi royals have been criticised after illegally closing off a beach in French Riviera town Vallauris for their family holiday. Getty Images

The Saudi royals are at the centre of a controversy after illegally closing off a secluded private beach in a French Riviera town for their family holiday.

The Saudi royals are scheduled to spend a couple of weeks at their mansion in southeastern France in Vallauris, which is situated adjacent to the Mirandole beach.

The Mirandole beach, which is only accessible by a tunnel was reportedly fenced off and a concrete slab was found next to the beach entrance.

Local authorities have condemned the act as illegal.

"We have had no planning application for this work," Vallauris Mayor Michelle Salucki told a local newspaper Nice Matin, reported France24 News.

"Local police have been alerted and have been told to remove this obstruction to public access.

"The law must be respected and no decree has been issued by the regional prefect [the chief representative of the French state's authority] blocking access to this public beach."

Meanwhile, the sub-prefect of the local town Grasse, Philippe Castanet, clarified the Saudis are in talks to fence off the beach, however the negotiations are still ongoing.

"These works went ahead before the ongoing negotiations between France and the Saudi authorities over the security arrangements during the royal family's stay in Vallauris had been finalised," Castanet told AFP News.

"This public beach will be completely closed off during the Saudi royal family's visit.

"We are still negotiating how they will be protected, by security agents or police, whether or not areas will be fenced off from the public, and exactly when we will be able to re-establish full public access to the beach."