An art historian raised the alarm after noticing that paintings attributed to Etienne Terrus showed buildings that were only constructed after the artist’s death in 1922.

Experts confirmed that 82 of the 140 works displayed at the Terrus museum in Elne, the artist’s birthplace in southern France, were fakes.

Many of the forged oil paintings, watercolours and drawings were bought with £140,000 of municipal funds over the past few decades. Others were given to the museum by two local groups that raised money to buy them by appealing for donations. Some were bequeathed by a private collector.