Louis Picamoles: Northampton Saints' forward returns to Montpellier
France international Louis Picamoles has left Northampton Saints to rejoin Top 14 side Montpellier for a "significant transfer fee".
The 31-year-old joined Saints last summer on a three-year contract and was nominated for the Rugby Players' Association player of the season award.
Picamoles has 62 caps and played all five games in this year's Six Nations.
Saints said the deal for the number eight will "underpin the future financial stability for his family".
Director of rugby Jim Mallinder had previously said there was no reason for Saints to sell Picamoles.
But Montpellier, where he previously played from 2004 to 2009, had reportedly been preparing a seven-figure sum to try to buy the number eight out of the remaining two years of his contract.
"I am proud to have played for Northampton Saints and I have enjoyed my time with the club," Picamoles said.
"I am grateful for all the support and friendship I have received from the club, the coaches, my team-mates and supporters."
Picamoles featured 20 times for Saints last season and the club said they "reluctantly agreed to the transfer", adding that the French Federation (FFR) want to see their internationals playing domestically.
Montpellier president Mohed Altrad confirmed: "Louis was the only French international player not playing in the Top 14.
"I am therefore delighted for Louis and the FFR that we have been able to secure his return to France.
"This is a wonderful opportunity for Montpellier to strengthen its squad with a truly world-class professional and fits perfectly with our long-term plans for the club."
BBC Radio Northampton's Graham McKechnie
Picamoles is irreplaceable - I know we're a given to hyperbole in sport, but he really is the best I've ever seen at number eight. He's got it all; immense power and incredible off-loading game.
You dread to think how Saints - who finished seventh in the Premiership - would have fared this season without him.
In terms of a replacement, this is very late for them to try and replace a player of his calibre. They will need another number eight, though Teimana Harrison and Mitch Eadie, who is joining from Bristol, are capable.
What it does mean is Saints now have a big chunk of money; they mustn't rush to spend it, but it is essential that at least some of the money goes into the squad. Who that will be is really too early to tell.