The Bundesliga's fastest ever goalscorer Karim Bellarabi has signed a new deal keeping him at Bayer Leverkusen until 2020, the club announced on Friday.

The 24-year-old Germany international, linked with a move to Chelsea and Liverpool, had already agreed the new deal in December.

"I've improved a lot in my development under coach Roger Schmidt this term," Bellarabi told his club's official website.

"I've become a much better player under his guidance and in his system."

Bellarabi entered the Bundesliga record books last August when scoring the fastest ever German league goal after a mere nine seconds.

The midfielder's lightning strike against Borussia Dortmund was two seconds quicker than the previous record held by Bayern Munich's Giovanni Elber.

He has had a stellar season, starting all of Bayer's 21 Bundesliga matches and finding the back of net on nine occasions.

"I've never enjoyed such trust as Roger Schmidt. I will do everything to repay him and Leverkusen," he said.

He made his full international debut for Germany in October in a 2-0 Euro 2016 qualifying defeat away to Poland.

Leverkusen, who are sixth in the table with only four points separating them and a place in the top three, head to fifth-placed Augsburg on Saturday.