French heavyweights Toulouse have signed highly regarded scrum-half Antoine Dupont from Castres, the record 19-time champions said on Wednesday.

"Antoine is an explosive player capable of breaking through any defence but also leading the team tactically with his efficient kicking and accomplished passing game," said Toulouse sporting director Fabien Pelous.

Dupont, who turned 20 earlier this month, moved to Castres in 2014 and has made 33 appearances in the domestic Top 14 while also playing in 10 European matches.