An unknown collection of 230 classic cars owned by a private collector in the Netherlands will come on the market next month, including a Lancia Aurelia Spider and Mercedes-Benz 300S Roadster.

The cars were owned by a Dordrecht businessman named as Mr Palmen, who started collecting them 40 years ago, housing them in two separate buildings and a church. Palmen could no longer keep his collection due to personal circumstances and Gallery Aaldering recently became the owner of what is said to be one of the largest barnfind collections in the world.

The entire collection is now under one roof and will be sold at a major online auction in May and June. Most of the cars, including Maserati, Lancias, Ferraris, Alfa Romeos, Jaguars, Aston Martins, BMWs and Facel Vegas, are in their original condition.

Temporary owner Nico Aaldering told the Telegraaf the collection is unique because Palmen did not focus on a brand or type. ‘He is a big car enthusiast and knew a lot about them, but he bought what he liked,’ Aaldering said.

Very few people knew about the existence of the huge collection until last year. ‘Mr Palmen lived like a hermit and did not let anyone into his life,’ Aaldering said.

His immediate neighbours were not aware so many cars were being stored next door either. ‘One of them told me that he had asked me several times to take a look inside, but that was always refused,’ Aaldering said.

The presence of the cars first emerged last year when there was a fire in one of the warehouses and the fire brigade were able to stop the cars going up in smoke.

The new owners will not be able to drive off in the vehicles because they are covered in dust and soot, and need a service. But they are in their original condition, Aaldering said. ‘Mr Palmen never drove them… and I have not spotted any signs they have been restored.’