Moldova international lock Andrei Mahu is to join London Irish from Russian side Krasny Yar Krasnoyarsk.
Mahu, 29, will arrive for the start of the 2020-21 season, having faced the Exiles in the 2017-18 Challenge Cup.
He has spent most of his time with eastern European sides, but also had a spell at Italian club Zebre.
"He will bring his experience to our pack and add more depth to our second-row department," Irish boss Declan Kidney told the club website.
The length of Mahu's contract has not been disclosed.