Real Madrid completed the signing of Brazilian midfielder Casemiro, the club announced on Monday.

Casemiro spent last season on loan at Madrid Castilla after arriving from Brazilian side Sao Paolo in December. He also made one appearance for Real Madrid against Real Betis.

Casemiro, 21, makes his stay at the Bernabeu permanent on a four-year deal after the club activated a six million Euro release clause in his contract.

"Real Madrid C.F. have used their purchase option to buy Carlos Henrique 'Casemiro' and as a result he will be a first team player at the club for the next four seasons," a statement read on the club's official website.

Casemiro becomes the team's second signing of the summer after Dani Carvajal arrived from Bundesliga side Bayer Leverkusen.