The BBC was plunged into fresh controversy yesterday over faked phone-ins after an inquiry unearthed serious breaches in six shows including the charity telethons, Comic Relief, Children in Need and Sport Relief.
Mark Thompson, the corporation's director general, ordered all phone-related competitions on television and radio to cease from midnight last night, while interactive and online competitions were also being taken down.
The announcement of a suspension came as Mr Thompson revealed six new instances of programmes featuring fake winners, in a presentation to the BBC Trust.
The move came after a review of about one million hours of output since 2005, following an internal investigation in the wake of a row over a BBC1 trailer, which wrongly implied the Queen had stormed out of a sitting with the photographer Annie Leibovitz.
In one of the latest incidents, a member of the production team for Comic Relief posed as a viewer in March, after the audience was invited to donate money by calling in to win prizes belonging to a famous couple.
The first two callers taken on air gave incorrect answers, during which time other waiting callers were lost. Then, a member of the production team posing as a caller was heard successfully answering the question on air.
In Children In Need - which the BBC describes as the "most important single event" in its calendar - during a broadcast from Scotland in November 2005, the name of a fictitious winner was read out on air after a technical mistake prevented genuine callers from getting an open phone line.
In Sport Relief last July, viewers were led to believe a member of the audience won a competition that was open to the public but the caller was part of the production team, as was a caller on BBC2's children's programme, TMi, last September.
Meanwhile, pre-recorded radio programmes of The Liz Kershaw Show were presented as if they were live, including a competition announcement that appeared to feature genuine listeners phoning in to take part, one of whom would win a prize on air.
White Label, a weekly pop programme on the World Service transmitted until April last year, announced fake winners for the CD prize slot in the show, when no winning entries had actually been received.
In fact, there were no competitions or prizes in shows during 2005 and 2006 and all the callers were members of the production team and their friends. The practice was only stopped when a new producer took over the programme in December last year.
Mr Thompson said the incidents were "totally unacceptable", while the shadow Culture Secretary, Jeremy Hunt, called it "a grim day for the BBC''.
Richard Tait, from the BBC Trust, said the disclosures had damaged the corporation's reputation. "We know that licence- payers really trust the BBC and value its reputation for integrity and honesty so we are very disappointed to be told about these cases. I think it is quite damaging in the sense that this is an organisation that is respected around the world..." he said.
The latest admissions cap a miserable period for the BBC, which was also fined £50,000 for a fake winner on Blue Peter.
Mr Thompson spoke of the importance of "going public" with the announcement of the various phone-in deceptions.
"It is right that we are open with the public when we have fallen short and that we demonstrate that we take this very seriously indeed. There is no excuse for deception. I know the idea of deceiving the public would simply never occur to most people in the BBC."