Le Garrec made 15 WSL appearances after joining the club in August 2019 and scored in the 3-0 win against Birmingham City at the Amex last November.
Powell explained, “Le has been back at home in France during the lockdown and realised how much she has missed her family.
“We’ve had lots of chats and she was very torn, but her family wanted her to stay and that was the deciding factor.
“She told me that she loved being part of the club and living in the city. She is very sad to be leaving but family comes first and we of course respect her decision and wish her all the best for the future.”
The club have released Kate Natkiel, Amanda Nilden, Sophie Harris, Fern Whelan and Ini Umotong while Maxime Bennink, who joined Albion on loan from Reading in January, has been released at the end of her contract.
Powell added, “Letting players go is never easy and there was a lot of discussion among all of the staff before we made what were extremely difficult decisions.
“I would like to thank Kate, Amanda, Sophie, Fern, Ini and Maxime for their commitment, dedication and hard work during their time here at Brighton.
“They have always been totally professional and great team-mates. We wish them well for the future and will of course support them if they decide to continue in the professional game.”