The French full-back earned the permanent deal after an excellent season on loan at the Riverside Stadium.

The 24-year-old, who arrived on loan from Lens in October, has accepted a five-year deal as manager Steve McClaren begins the latest phase of his rebuilding work.

McClaren told the club's official website: "He is the right age, the right character.

"He has come in and immediately settled down from day one and he has proved he has been a great acquisition for this football club."

Queudrue has started 34 of the 35 games Boro have played since his arrival, including the FA Cup semi-final defeat by Arsenal.

But McClaren's latest signing will not figure in the final game of the season at Leeds next Saturday after being sent off against Blackburn last month.