London, UK - The royal family experienced a major shock last year when there was a robbery at their estate, but now, the plot has thickened: the police are closing the investigation with no leads on the suspects.

"We've conducted an investigation following a number of lines of enquiry," law enforcement said, per The Sun.

"The investigation has now been filed pending any further information coming to light."

According to an insider, police were unable to find any concrete leads in the case, saying, "They have tried to investigate it thoroughly, but still don't have anything at all to go on."

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"It is pretty worrying and frightening that it has now just been dropped," the source added.

"It is not like they are the only force to struggle to solve burglaries at the moment – but you’d have thought the Windsor Castle estate would be more secure than pretty much anywhere

The perpetrators entered the grounds of Windsor Castle last October, scaled a six-foot fence, and stole farm vehicles from a barn.

Notably, Prince William and his wife, Kate, were on the grounds of the estate at the time, likely asleep with their three children in the nearby Adelaide Cottage on that fateful Sunday night.