Giedo van der Garde is set to take legal action against Sauber, claiming that he was unfairly dismissed from the Swiss outfit.
Van der Garde switched from a race seat with Caterham to a reserve role at Sauber for 2014, where he participated in free practice sessions with a view to a race seat for 2015.
Van der Garde believes that he holds a valid contract to race for the team this season, but that Sauber reneged on the agreement and opted to sign Felipe Nasr and Marcus Ericsson.
Australian media reports that Van der Garde has lodged documents with the Victorian Supreme Court in Melbourne and is seeking a hearing on Monday.
Local media claims that Van der Garde was successful after taking his case to an Arbitration Institution in Switzerland, where the team is based.