Nic Groom will leave Saints with immediate effect as the scrum-half heads back to South Africa to join the Lions in Super Rugby.
The Johannesburg-based franchise are currently struggling with injuries and Groom will be a welcome addition to their squad.
The 28-year-old sees a near two-season spell at Saints come to an end, having scored seven tries in 51 appearances during his time in England.
He had been competing with compatriot Cobus Reinach for the starting spot this season.
But Reinach and talented youngster Alex Mitchell will now get a chance to stake their claim for the No.9 shirt for next season in the final four games of this campaign.
“I have loved the opportunity to come over to the UK and play for such a great club in Northampton Saints,” said Groom, who was out of contract this summer.
“But the time has come for me to return to South Africa.
"An opportunity has come up to return home, and I am grateful to the club for allowing me to head back early to try to make my mark.
“The Northampton Saints, the supporters and the local community will always have a special place in my heart.
"Playing at Franklin’s Gardens in front of these fans has been an honour, and I will cherish every moment of my time here.
“I want to thank my team-mates, coaches and the friends that I have made since moving, and I wish them all the best for the future.
"I leave Northampton a better man with a heavy heart, but I have no doubt the club will be flying in no time – come on you Saints!”
Saints interim head coach Alan Dickens said: “Groomy has had a big impact in his two years at Franklin’s Gardens.
"He has had a very positive influence, both on and off the pitch, and I am sure he will be missed by many Saints supporters.
“But he leaves with our very best wishes and I hope he can achieve everything he wants to back home in South Africa.”