The incident is reported to have taken place in the first-class cabin of a United Airlines flight. The woman told the cabin crew that a man assaulted her while other passengers were asleep.

United staff reported the situation to police before arriving in London.

The 40-year-old was arrested by authorities at Heathrow Airport on 31 January. He has since been released under investigation.

The woman has been taken to a rape counselling facility and given additional support by a specialist team.

The Metropolitan Police are “aware of an incident on an inbound flight,” according to a spokesperson.

United Airlines told Euronews Travel that the “crew called ahead and notified the local authorities as soon as they became aware of these allegations.”

The airline added, “we will cooperate with law enforcement on any investigation.”