Argentinian tight head prop Ramiro Herrera has signed for French rugby champions Castres ­until 2016, the Top 14 side confirmed Tuesday.

The 25-year-old arrived as medical cover from Argentinian club side Hindu early in April to fill the gap left by injured duo New Zealander ­Karena Wihongi and Georgian Anton ­Peikrishvili.

Herrera impressed in the two Top 14 matches he played with Castres.