Dragons centre Jamie Roberts will leave the region at the end of January for "personal reasons" and is set to link up with the Waratahs in Australia.
Roberts has been granted an early release from his Dragons contract with the blessing of director of rugby Dean Ryan.
The 35-year-old will move to Australia to join his Sydney-born partner who is expecting their second child.
"It is with a heavy heart I'm leaving the Dragons," said Roberts.
"I'd like to personally thank Dean for understanding my personal circumstances.
"As my Sydney-born partner is expecting our second child in March, we feel the best decision for our family is to be surrounded by her support network in Sydney during this period."
Sydney-based Waratahs open their Super Rugby campaign against Fijian Drua on 18 February and are expected to confirm the Roberts signing imminently.
Roberts joined the Dragons in August 2020 and has scored five tries in 23 appearances for the Gwent region. Roberts has been part of five Dragons victories and 18 defeats.
Dragons have lost nine out of 10 competitive games this season.
Roberts' final appearance could be against Benetton in the United Rugby Championship on 28 January at Rodney Parade, although that has yet to be confirmed.
"Although it'll be difficult leaving, I do so with many fond memories," added Roberts.
"As well as enjoying wearing the jersey and playing, I've taken great satisfaction in supporting and witnessing the growth and development of younger players in the squad, many of whom are destined for success in the game.
"It's been great fun playing back at Rodney Parade, where my parents took me as a young lad growing up to watch the Black and Ambers.
"Although supporters haven't been able to attend as much as they'd have liked, for obvious reasons, I'd like to thank them for their support.
"I wish the coaching and playing group nothing but the very best moving forward."
Roberts returned to Welsh domestic rugby after a seven-year absence when he joined Dragons after a short stint with the Stormers in South Africa.
He left Cardiff Blues in 2013 for Racing 92 in France and has also played for Harlequins and Bath in England.
Roberts won the last of his 94 Wales caps in November 2017 and went on two British and Irish Lions tours, in South Africa in 2009 and Australia four years later.
"We thank Jamie for his time at Dragons and the support he has given us, helping stabilise the environment and encouraging youngsters to come through," said Ryan.
"We support what has been a difficult decision for him to make.
"We wish him a safe trip over to Australia and look forward to welcoming him and his family back to Rodney Parade in the years to come."