London Welsh head coach Lyn Jones has confirmed that the club have completed the signing of Argentine forward Julio Farias Cabello.
The 34-year-old, who has 19 international caps for his country, had been with Tucaman in his home nation.
"Julio is a quality player with a high work-rate and will add a great deal of ability to our squad for the final push in the Aviva Premiership," said Jones.
"We've got eight games to go and we need as much depth to our squad as possible to be as competitive as we can in mid-February as we need to be in May."
Cabello can also play second row.