The robbery took place at Amsterdam’s Schipol airport back in February 2005, when a gang dressed in uniforms hijacked an armoured truck in a high security area.
The truck’s drivers were forced out at gunpoint and made to lie on the ground before the thieves sped off.
No one was hurt in the heist.
But while some of the stolen diamonds were found in a getaway vehicle immediately after the robbery, the rest of the haul – valued at £35m – has never been recovered.
Police in the Netherlands said in a statement that five men and two women, all Dutch nationals, have now been arrested in Amsterdam and Valencia, in eastern Spain, in connection with the 2005 raid and money laundering.