Connacht lock Mike McCarthy will depart the club at the end of the season to join Leinster after failing to agree a new deal at The Sportsground.
The move was confirmed in a statement by Connacht chief executive Tom Sears, but he has condemned the actions of their fellow Irish outfit.
"We are bitterly disappointed to lose Mike McCarthy, who has been a popular senior member of our squad," said Sears.
"While disappointed, particularly given the continued success of Connacht Rugby in recent years, we respect the individual player's decision and wish Mike every success in his future playing career.
"We have been aware of Leinster's interest in Mike for some time. It is disappointing they have persistently targeted Connacht players in recent years, particularly when often not in the best interest of Irish Rugby."
Fionn Carr and Sean Cronin have also reportedly been targeted by Leinster in recent seasons.
