Scarlets head coach Glenn Delaney will leave the region with immediate effect.
The decision was announced less than an hour after Delaney had taken charge of the Pro14 Rainbow Cup victory against Ospreys.
Delaney's departure comes fewer than three weeks after it was announced he was being promoted to director of rugby next season.
Former Wales scrum-half Dwayne Peel returns to Scarlets as head coach next season.
The players were told in the Parc y Scarlets changing room following the defeat of Ospreys. Backs coach Dai Flanagan will take charge of the region for the rest of this season as interim head coach with Peel arriving from Ulster in the summer of 2021.
It has been a disappointing season for a Scarlets side that finished third in their Pro14 conference and suffered a heavy 57-14 Champions Cup last-16 defeat against Sale with a change now coming in the coaching structure.
"Today I announce that I will be leaving the Scarlets," said Delaney in a Scarlets statement.
"It has been a great pleasure to coach this fantastic club. It has been the most difficult of seasons with the global pandemic creating many challenging issues that the staff and team here have dealt with incredibly well. I leave with great memories of two wonderful years out west.
"We have enjoyed some great times, which in the first year we were able to share with the supporters being there. I won't forget the European games away to Toulon, Bayonne and London Irish where the travelling support was simply unbelievable. Our Champions Cup match against Bath this season was one that I know the travelling faithful would have loved.
"I know that the club is in great hands moving forward into the new season and I wish it nothing but the best. I want to say a huge thank you to the great staff and the outstanding playing group here at the Scarlets and of course the supporters. I've loved everyday working with you all."
In February 2020, Scarlets announced they were promoting Delaney to replace fellow New Zealander Brad Mooar as head coach for the 2020-21 season.
Delaney had been defence coach but stepped into the top role after Mooar left Scarlets to join Ian Foster's New Zealand backroom staff.
In May 2019, the region had appointed Delaney as defence coach following the departure of Byron Hayward to Wales.
Delaney had spent seven years as director of rugby at Nottingham before becoming London Irish's forwards coach, head coach and finally head of rugby operations.
Delaney returned to New Zealand to join Mitre 10 Cup side Canterbury in December 2016 and led them to a ninth title in 10 years, before joining the Highlanders in 2018 as defence coach and then linking up with Scarlets.
"We would like to thank Glenn for his wholehearted commitment to the Scarlets during his time here and wish him well for the future," said Scarlets executive chairman Simon Muderack.
There is no indication from the Scarlets board yet whether they will replace Delaney and appoint a new director of rugby or put Peel in overall charge when he arrives.