Bordeaux's Rams complaint
By Patrick Haond
Last Updated: 01/01/70 1:00am
The right back arrived at Pride Park last November in a £3 million deal but Bordeaux have yet to receive the cash.
They have contacted a British law firm to study the case and are preparing to submit their complaint to Fifa.
Grenet has barely featured for The Rams since John Gregory was appointed manager earlier in the year and has been informed he has no future with the club following their relegation to Division One.
However, Bordeaux do not want to re-sign the full back and are determined to settle the matter.
"When I am selling wine to someone, until I get the cheque, the wine belongs to me," said Bordeaux chairman Jean-Louis Triaud.
"It is a very complex case and we won't give up. There is an important loss of profit."
Grenet is currently on holiday but has been linked with a return to Le Championnat with Rennes.