The 25-year-old was attacked after becoming separated from friends at the Queen Spectacular event at around 11pm.

She was grabbed by the two men at the Lab Crossroads, off Lime Trees Avenue, as she returned to the main car park after the event's firework display finale.

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They pulled her into a wooded area and attacked her. Police said she was left 'shocked and extremely distressed'.

Both suspects are described as aged 19 to 20, one is of slim to medium build and was wearing a blue baseball cap and tracksuit; while the other is described as being of medium to heavy build with thick wavy blond hair, and wearing tracksuit bottoms.

DI Mel Bowden said: "This was a traumatic experience for the victim, to be attacked by two strangers having lost her friends".

"We are keen to speak to people who may have seen two men hanging around this area, and would ask anyone who took digital photos or moving footage around Lab Crossroads at 11pm to contact the police."

Ian Deans, property manager at Clumber Park, added: "The National Trust is extremely concerned to hear of this assault and is co-operating fully with Nottinghamshire Police during their investigations.

"Our thoughts are with the woman involved. Incidents of this serious nature are extremely rare at Clumber Park."