De Vries will race full time in F1 this year with AlphaTauri after being signed as Pierre Gasly's replacement following the Frenchman's move to Alpine.
At 27, de Vries will be one of the oldest full-season rookies in recent memory, but clinched the seat after impressing upon a late call-up for his F1 debut at Monza last year, finishing ninth for Williams when Alex Albon was ruled out through illness.
But de Vries is now being sued through the Dutch courts by Jeroen Schothorst, who claims the AlphaTauri driver withheld information and breached agreements relating to a loan agreement in 2018.
According to Dutch newspaper FD, de Vries took out a €250,000 loan from Schothorst's investment company, Investrand, to help secure an F2 seat with Prema in 2018.
This agreement allegedly came charging 3% interest per year as well as a cut of future income from F1 activities. It also stated the loan would be waived if de Vries was not an F1 driver in 2022.
De Vries paid €190,000 in interest to Schothorst, but because he did not have an F1 deal in place for 2022, he was under the assumption that the loan would be written off as per the agreement.
But Schothorst claimed in court this week that de Vries had failed to provide the required information about his earnings and contracts during the term of the loan, and is now requesting those details, including those relating to his AlphaTauri F1 deal.
Schothorst is also contesting the definition of his test and reserve role in F1 last year, which saw him formally work for Mercedes while stepping in for its customer teams when required.
"Let me, first of all, say that I think it is fantastic for Nyck that he has become successful as a Formula 1 driver and that there will be two Dutch drivers at the start of the Dutch Grand Prix in August," said Schothorst in a statement released to the Dutch media.
"We invested in de Vries' career at a crucial moment and when nobody else wanted to do it anymore. We now have different opinions on the interpretation of the agreement we entered into with each other at the time.
"Things like that happen and as a result, we, unfortunately, cannot escape taking the matter to court. We really would have preferred this to be different, but that does not alter the fact that, as a motorsport fan, I wish Nyck all possible success in the continuation of his career."
De Vries has denied all of the allegations, claiming that he provided Schothorst with all of the necessary information about his contract.
According to De Telegraaf, de Vries's lawyer, Jeroen Bedaux, claimed the F1 driver has proposed to repay the €250,000 loan on top of the €190,000 interest he has already paid, but this proposal was rejected by Schothorst.
"Everything shows that Investrand cannot stomach the fact that De Vries became a Formula 1 race driver in 2023, and not in the last year of the agreement," said Bedaux in court on Tuesday.
Bedaux also claimed that another factor involved is that de Vries politely declined Schothorst's offer to become his F1 manager.
A ruling is expected from the Amsterdam court in early February.
