Louis Picamoles has rejoined Top 14 club Montpellier

Saints have accepted a "significant transfer fee" for number eight Picamoles, who has fallen in line with the French Rugby Federation's desire for all its internationals to be playing in the Top 14.

"The 31-year-old has received a proposal from Montpellier which will underpin the future financial stability for his family," Saints said in a statement.

"The club has therefore reluctantly agreed to the transfer and accepted a significant transfer fee for his services.

"This fee will be reinvested into the playing squad to ensure Northampton Saints continues to strive for success on the pitch. To achieve this, the Saints is looking to further strengthen the squad with new signings in addition to the world class talent already confirmed for 2017/18.

"The Saints' management would like to thank Louis for his contribution to this season and wish him all the best for the future."

Picamoles, voted Saints' player of the year, was reported earlier this month to have signed a pre-contract agreement to rejoin Montpellier, where he began his career, after France's tour of South Africa this summer.

He has made more than 60 appearances for France after making his international debut against Ireland in the 2008 Six Nations and joined Northampton from Toulouse on a three-year contract in 2016.