South Africa lock Alistair Hargreaves has agreed a deal to join Saracens next season.
The 25-year-old currently plays for Super 15 side the Sharks, but will switch to the Premiership for the start of the 2012/13 campaign, where he will play alongside fellow Springboks John Smit and Schalk Brits.
"Everybody in South African rugby knows there is something special happening at Saracens, and I can't wait to get stuck in and make a contribution to the continuing development of the club," said Hargreaves, who has won four caps for South Africa, in a statement.
"This is a fantastic opportunity for me at a crucial stage of my rugby career."
Mark McCall, Saracens' director of rugby, said: "Alistair has a fantastic pedigree in SA Rugby, and we are confident he will flourish in our environment."