An edition of Brand's 6Music radio show was billed as live but was pre-recorded - and a member of staff posed as a competition winner. Listeners who called or texted to take part had no chance of winning.

Radio 1 star Jo Whiley's show has been found guilty of faking a competition entrant for the second time.

On this occasion, production staff made up the name of a competition participant. It occurred three weeks after another fake winner was put on air, an incident which came to light in October.

Listeners who texted into the programmes are to be offered compensation by the BBC. An apology will be broadcast on both networks this week.

Both breaches occurred in spring 2006. It is unclear why they did not show up in a previous trawl for evidence of misconduct.

The BBC downplayed the two new discoveries and said an "action plan" for cleaning up the Corporation was well under way.

"Neither of the two new cases revealed any new types of failing editorial practice which have not already been captured by the action plan, and both predate the commencement of the action plan," a spokesman said.

BBC director-general Mark Thompson revealed the two new breaches during a meeting with the BBC Trust. He said: "I am pleased to have been able to report considerable progress in delivering our action plan, which we will continue to pursue with vigour."

The Corporation suspended phone-in competitions last year after a spate of scandals involving the likes of Blue Peter, Comic Relief and Children In Need. A phased return of competitions begins this month, with Match of the Day's Goal of the Month and Ken Bruce's Pop Master the first to be reinstated.