A Tube train restored to its original 1938 condition has been vandalised, leading to the cancellation of a heritage event.
The London Transport Museum planned journeys along the Piccadilly line between Acton Town and Oakwood on Sunday, with ticketholders enjoying a 50-minute trip between the stations.
The museum said it was working with conservators to find out the extent of the damage.
It said British Transport Police (BTP) was investigating the vandalism.
Elizabeth McKay, from London Transport Museum, said she was “devastated” by the news.
She added: “Our heritage Tube train operations are a wonderful way for the public to experience the history of the capital and the proceeds from ticket sales support our work as an education and heritage charity.
“It is truly disappointing that vandals would seek to ruin this experience for people and cause damage to such an iconic, heritage vehicle.
“We will be working with London Underground specialists and conservators to understand the extent of the damage and return the train to its former glory.”