A group of 25 people face trial in Morocco in connection with the alleged robbery of luxury watches and jewellery from one of King Mohammed VI's royal palaces.

They have been accused of belonging to a criminal gang that reportedly carried out the raid on a palace in Marrakesh, according to local media.

The alleged ringleader of the organisation, according to Hesspress, a Moroccan news website, was a female employee at the palace, but she was also reported to have been aided by palace security staff and Moroccan jewellers.

No details of the stolen watches or jewellery nor the date of the alleged crime were disclosed by Moroccan authorities.

A trial is expected to start next week in Rabat, the Moroccan capital.

King Mohammed VI is known to have a large collection of expensive timepieces and jewellery.

In September 2018, the Moroccan monarch was reported to have acquired a Patek Philippe Nautilus watch, encrusted with 893 diamonds and worth $1.2m.

The Hesspress report, first published on Monday, alleged a woman who worked at the royal palace in Marrakesh was the principal suspect in the robbery.

The Moroccan royal household neither confirms nor denies reports regarding the king.

All those detained are accused of robbery and "abuse of confidence", report local media, because they either worked at the palace or were in some way connected to the royal family.

The Al Massae newspaper reported the gang stole other valuables, as well, but did not specify details.

"This is extremely unusual that a robbery should take place at a royal palace," Ali Lmrabet, a Moroccan writer and journalist, told Al Jazeera.

"The last time it happened was about 40 years ago. Normally, anything to do with the security of the king is shrouded in security, so it must mean that someone near the king has authorised that this information be disclosed."

In 2016, Mohammed VI gave then-US President Barack Obama a golden brooch decorated with diamonds and rubies, as well as silver earrings and a watch encrusted with emeralds and diamonds.

The US Federal Registry valued the gifts at $101,200, and the jewellery was deposited in the National Archive and Register - which holds gifts presented to US presidents.

"Security around King Mohammed can sometimes be lax," Ignacio Cembrero, a Spanish journalist who covers Morocco for news website El Confidencial, told Al Jazeera. "I have seen him go on private trips around cities with just one bodyguard car in front of his own."

Cembrero said the Moroccan monarch remained a popular figure among his people, but his image had been damaged in recent years by frequent trips abroad.