On 18 March 1990 two police officers entered the Isabella Stewart Gardner Museum in Boston – they told security they were responding to a late-night disturbance and asked to be let in. The guard allowed the cops in through the employee entrance but got a surprise – they were art thieves. After handcuffing the two guards, they stole 13 famous artworks by Rembrandt, Vermeer and Degas, walking away with art today valued at $500m.

It remains the world’s biggest unsolved art heist and the museum announced last week that they are extending a $10m reward for art stolen 28 years ago. According to Steve Kidder, president of the museum’s board, the museum doubled the reward and made it indefinite because they remain hopeful that the art will make a comeback.

“This reward demonstrates the commitment of the museum and its board of trustees to the recovery of these important works,” Kidder said in a statement. “We are the only buyer for these works and they belong in their rightful home.”

The artworks stolen include Rembrandt’s Christ in the Storm on the Sea of Galilee, as well as his A Lady and Gentleman in Black. Johannes Vermeer’s The Concert was also stolen, as was Govert Flinck’s Landscape with an Obelisk. When one walks into the museum today, the empty picture frames hang where the masterpieces were once displayed. Read more