Squatters invaded an empty property in West Hampstead over the Bank Holiday weekend, disturbing neighbours who say they were intimidated and kept awake by late night parties.

According to nearby residents, the squatters broke into 65 Maygrove Road – a former office building – last Friday.

At one point, approximately 100 people were reported to be inside. Eye-witnesses said there were dozens of people coming and going from the property, some arriving in cars and others sitting outside smoking.

They said police were seen going to the property several times but the squatters were only moved out on Monday.

Yesterday two security guards were stationed at the building, where litter and furniture could be seen at the front entrance.

Squatters made another attempt to break into the property, which has been vacant for at least two years and is due to be demolished, on Tuesday evening.

Tania Moor, who lives opposite the building, said: “We didn’t hear anything because we’re in the attic room but my parents-in-law were staying in the front bedroom and they were pretty disturbed.

“The first thing I heard about it was on Monday when my in-laws said ‘Have you seen everything that’s going on?’ We looked outside and saw a man washing outside with a bottle of water.

“My in-laws said they were woken up with the noise at 4am and they heard a crash which must have been when something went into the wall near the building.”

In 2011, a doctor and his heavily pregnant wife won a court ruling to evict squatters from their £1million West Hampstead house after being locked out for two weeks.

Consultant neurologist Oliver Cockerell was forced to spend thousands of pounds on legal fees to win his case.

Last August a change in the law made squatting illegal in residential buildings. However, squatting in commercial buildings is not in itself a crime.

Mrs Moor added: “My neighbour said she was glad to see a security guard there.”

A 29-year-old man is due to appear in court charged with assaulting a police constable on Monday in Maygrove Road.