Mischa van Gelder let men into his vault, let them tie him up and claimed stolen stones’ value on insurance.

One of the most renowned diamond dealers in the Netherlands has been convicted of fraud and money laundering after staging an armed robbery of €4.1m diamonds from one of his stores as part of an insurance scam.

Mischa van Gelder, 55, told a court in Amsterdam that he now found his plot “incomprehensible” but that he had been motivated by financial difficulties when he hatched it with three other men in 2016.

I wasn’t like that, I’m not like that. I did something terrible,” he told the court. “I was in a panic.

Van Gelder, whose family company, Van Gelder Diamonds, has sold to private individuals and traded in wholesale diamonds since 1904, pretended to police that he had been forced at gunpoint to open his vault during a raid.

But in reality Van Gelder had organized the whole thing. He had let the men into his vault, where he was voluntarily tied up and locked in. He was released after calling his daughter.

Van Gelder had agreed that his three accomplices could keep the diamonds from the vault while he would seek to claim back their value through his insurers.

Before Van Gelder was arrested, his insurer paid out €3.5m. After his arrest, one of the three men he had hired to stage the raid, named in court as Danny S, sought to blackmail him with recordings of their arrangement.

Van Gelder, who has already served 76 days in prison, was given a partially suspended prison sentence of six months and a maximum community service order of 240 hours.

The suspect went very far and scared a lot of people,” the judge said. “He made the people around him believe that an armed robbery had taken place. As a result, the police had to conduct an unnecessary large-scale investigation.”

Danny S was sentenced to a 90-day suspended prison term and 200 hours of community service for fraud. The two other men involved are yet to be caught. Van Gelder has paid back the money scammed from his insurer. The diamonds are still missing.

At the time of Van Gelder’s arrest, his father, Jack, then 76, issued an apology and said he would take over the business.

He said: “We are all shocked and deeply moved by these developments. I have personally taken charge of our family business again and have taken the necessary measures to ensure continuity. On behalf of the company I would like to apologize to the police, the public prosecution service, the insurer, customers, suppliers – everyone who has been misled by Mischa’s actions.