RB Leipzig have announced that Castello Lukeba has extended his contract with the club until June 2029.

The 21-year-old's future has recently been the subject of much speculation, with a number of teams, namely Real Madrid and Chelsea, believed to be interested in signing him during next summer's transfer window.

Lukeba made the move to Leipzig from Lyon in 2023, and he has represented his Bundesliga side on 50 occasions, including nine appearances in all competitions during the 2024-25 campaign.

Leipzig have confirmed a contract extension for Lukeba, which increases a pay rise, but according to journalist Florian Plettenberg, there is a €90m (£75m) release clause, which becomes active in the summer of 2025.

"The move to Leipzig was the perfect one for my development. I soon got lots of minutes and was able to take on responsibility. I've always had the support of everyone at the club, our fans and my teammates – RB Leipzig now feels like my second family," the defender told his German club's official website.

Lukeba calls Leipzig his "second family"

"The setup here makes it so easy for young players like me to settle in and improve with each day. Being able to train at the highest level and regularly play against the best teams in the world is simply fantastic! I'm looking forward to playing many more games for RB Leipzig and I'll do my absolute best to help us be successful.

"I would like to pay a special thanks to our amazing fans, who support us so passionately at each game. It also pushes me to play better and means a lot to me. I like celebrating and dancing with them after victories – I really value this special connection."

Meanwhile, Leipzig sporting director Rouven Schroder added: "In just a year, Castello has developed into one of the best defenders in the Bundesliga. He's played a big part in the solidity of our defence so far this season. He's not only a tough tackler, but also someone that can play a key role in our build-up play from the back.

"His tackling, passing, composure on the ball, pace and versatility – which allows him to play as both a centre-back and left-back – make him an outstanding footballer. We're really pleased that Castello has put pen to paper on an even longer contract at RB, as well as the fact that he sees his future in Leipzig."

Could Lukeba still leave Leipzig next summer?

If there is indeed a €90m (£75m) release clause in his new contract, then clubs will have to be prepared to pay out a significant sum to secure his signature during next summer's transfer window.

The world-record fee for a defender is €90m (£75m), which Manchester City paid for Josko Gvardiol, with the Croatia international arriving at the Etihad Stadium from Leipzig in 2023.

Harry Maguire is second in the list, having cost Manchester United €87m (£72.4m) from Leicester City in 2019, so Leipzig are in a very strong position when it comes to Lukeba's future, as it is tough to imagine any interested clubs paying his release clause.

That said, if he continues to impress throughout the campaign, then the France international could find himself at a major club in the not too distant future, with Man United also believed to be among his admirers.