Johnnie told listeners he was facing 'a toughie'

The 58-year-old told listeners of his Drivetime Show that it was "a toughie".

"This is normally something that someone in my position would keep very much close to their chest," he said.

"But given the very public nature of this job and the occasional time off I may be taking in the future it would be much easier for me to say (that) five weeks ago I was diagnosed with cancer in the form of non-Hodgkins lymphoma."

Walker said he had what is thought to be a very treatable form of the disease.

He added: "I'll kick off my treatment tomorrow so I'll be taking next week off to see how it goes."

We offer Johnnie every good wish and will give him all the support he needs during his treatment Jim Moir BBC 2 controller

Walker, who has an audience of nearly five million, married his wife Tiggy only in December last year.

He rounded off his show with Simon and Garfunkel's Bridge Over Troubled Water, dedicating the song to anyone who was in the same position.

Radio 2 controller Jim Moir said on Thursday: "We offer Johnnie every good wish and will give him all the support he needs during his treatment."

Cocaine allegations

Walker made his name on the pirate station Radio Caroline in the 1960s.

He joined Radio 1 in 1969, serving on the BBC's flagship pop station and rock station for seven years and was respected for his love of music.

He moved to Radio 2 in 1998 to take on a Saturday afternoon slot, but by the end of the year he was on the weekday Drivetime Show.

Walker was suspended by the station in 1999 after allegations about cocaine use were published in a newspaper.