The retired Preston Buses buses were being stored at Walton-le-Dale’s Park and Ride site at the Capitol Centre when they were broken into over the last Bank Holiday weekend.
Pictures show the vehicles with severe front-end damage, deep scrapes along the sides, smashed windows and one with a tree inside.
A spokesman for Preston Bus said: “They were older buses and had been taken out of service. They were expected to sell very quickly, as they are in demand by collectors. We advertised some for sale late last year and had a huge response via our Facebook page.”
The total cost of the damage has not been revealed, but Preston Bus were selling eight Leyland Olympian Double Deck Buses late last year, each one priced at £2,500 plus VAT and tyres.
Police have been looking at CCTV and forensic evidence, but enquiries are still ongoing.
Preston Bus believe the damage was a targeted act by an adult, “and not the result of mindless actions of youths”, adding: “This was much more than the odd stone thrown through windows.”
Anyone with information on matter is asked to call police on 101 quoting log reference 571 of May 2.