Freddie Burns, Leicester's match-winner in last season's Premiership final, will leave the club in February to join New Zealand-based Highlanders.
Leicester said they had agreed for the former England international, 32, to be released early from his contract.
"At this stage in my career, the opportunity was one I saw as too good to turn down," said Burns.
Burns has made 114 appearances in two spells with Leicester, initially joining in 2014 from Gloucester and leaving for Bath three years later.
After time playing in Japan, he returned to Welford Road in the summer of 2021, with the highlight of his second stint with Tigers being the drop-goal that ended Leicester's nine-year wait for a league title.
Burns added: "My return to this club was unbelievable - to be a part of a group like this with players who are so tight and committed to one another.
"The way it has played out exceeded anything I could have dreamed of happening.
"To have had the moments we have had together in the past few seasons, not just the final win, has been like a dream and something I will never, ever forget."