The authority said these were serious breaches of the Broadcasting Act, and the fines were the maximum penalty which could be imposed under the legislation.

Xfm: Breakfast shows under fire

Rock station Xfm, which is owned by Capital Radio, broadcast material including bestiality and offensive language in two breakfast shows.

The offending shows included the presenter, Tom Binns, and a listener discussing a pornographic video featuring acts of bestiality in a phone-in about "the worst job in the world".

Other items included references to sexual matters in "crude and offensive" language, the authority said.

Chairman Sir Peter Gibbings said the authority's members were "appalled" by the material.

"These broadcasts heedlessly ignored the requirement that the portrayal or description of bestiality must not be broadcast," he said.

"The fact that this material was broadcast at breakfast time, when a significant number of young people might be expected to be listening, makes the offences all the more serious."

The whole authority condemns this kind of broadcasting, which demeans the radio medium. We are determined they should not be broadcast again.

Radio Authority chairman Sir Peter Gibbings

The authority said its members were "not left fully confident" that Capital Radio had taken steps to ensure that further offences were not committed by Xfm.

It warned that the station risked losing its licence unless it introduced measures soon.

Hallam FM, owned by the Emap group, broadcast two late-night programmes which contained descriptions of paedophilia and condoned rape.

Sir Peter Gibbings described the shows as containing material which was "deeply offensive, indecent and degrading".

He said: "The irresponsible treatment by the station of such serious topics as child abuse, rape and violence against women is wholly unacceptable.

"The whole authority condemns this kind of broadcasting, which demeans the radio medium. We are determined they should not be broadcast again."

Bob Geldof: Xfm appointment caused controversy in 1998

Hallam FM, which plays mainstream pop music, also fell foul of the law by not logging tapes of the offending shows.

But Sir Peter said he welcomed steps by Emap to ensure the breaches were not repeated.

A Hallam FM spokeswoman said DJ Tim Shaw was sacked following the offending broadcasts.

"The comments made were completely unacceptable and will never be tolerated," she said.

The record fine and threat from the authority is the latest blow in Xfm's troubled history.

It was launched in 1997 as a specialist alternative rock station, but quickly hit financial difficulties and was bought by Capital Radio in July 1998.

Listeners reacted angrily when Capital changed the station's output to a US-style modern rock format, and introduced Bob Geldof as a temporary drive-time DJ. The station was fined �4,000 after the authority received a record 600 complaints.

An Xfm spokeswoman said: "We regret the incident and we will pay the fine. We acknowledge the seriousness of the situation and are working to ensure it never happens again."