Tim Westwood is to leave Radio 1 after almost 20 years in a shake-up of the station's schedule.

The hip hop DJ - affectionately known as the Big Dawg - will also leave sister station Radio 1Xtra as both services revamp their weekend shows.

Westwood, 55, has been hosting a two-hour Saturday night show which is broadcast on Radio 1 and 1Xtra. He has also hosted a drivetime show for the digital station until last year.

He was famously injured in a drive-by shooting in south London in 1999 after a gunmen opened fire on the Range Rover in which the DJ was sitting after playing a set at a festival.

Radio 1 controller Ben Cooper said: "I'd like to thank Tim for the last 20 years on Radio 1. His passion for hip hop is legendary. I wish him all the very best."

The network has announced new Saturday night shows for presenters Charlie Sloth, MistaJam and DJ Target which will be aired on both stations.