Former All Black star Jonah Lomu is claiming more than 550,000 euros ($A695,000) in backpay and damages from his one-time French club Stade Phoceen, his lawyer has told the labour relations board.
Lomu played for Stade when they were known as Marseille-Vitrolles in 2009, competing in the Federale 1 (third) division.
The New Zealander was 34 years old at the time and, at the tail end of his career, only played a few games for the club, which has since gone into adminstration.
Lomu's lawyer, Assia Bennezzar, said the former winger's complaint had been filed on October 30 and went before the labour relations board in Marseille on Wednesday.
Regarded as rugby union's first global superstar, Lomu rose to prominence with his devastating performances in the 1995 World Cup and also played a major part in New Zealand's 1999 campaign.
He still holds the record for most tries at the World Cup, with 15 in total, and scored 37 tries in 63 Tests for New Zealand before illness eventually cut short his playing career.
Lomu was diagnosed in 1995 with the rare kidney disorder nephrotic syndrome and underwent a transplant in 2004, receiving an organ donated by friend and New Zealand radio broadcaster Grant Kereama.
But he revealed last month that that donated kidney had failed and he needed a new transplant. He was later admitted to hospital to undergo dialysis treatement before being released.