The Blue Peter apology has become a feature of the show that appears as regularly as charity appeals and sticky-backed plastic.

In March, the presenter Konnie Huq apologised to viewers after a member of the studio audience was chosen to pose as a competition winner after 14,000 phone-in entries had been registered. Huq told viewers: “We’d like to say sorry to you because when this mistake happened we let you down.”

In 1998, Lorraine Heggessey, head of children’s programming at the BBC, had to explain to viewers why the presenter Richard Bacon had been dismissed from the show. He had been found to be taking cocaine.

“Many of you will know that there has been a sad event,” she told viewers, explaining that Bacon had taken an “illegal drug”. “Richard admits he has done this and very much regrets it. However, I believe Richard has not only let himself down and the team on Blue Peter but he has also let all of you down badly.”

Last year, Richard Marson, the Blue Peter editor who lost his job over the phone-in scandal, reported another “sad but necessary short-term step”. The Blue Peter badge scheme had to be suspended because a thriving internet trade meant that people were using unearned badges to gain free entry to attractions.

Scandal has long followed the show. In 1962 Petra, a newly introduced mongrel puppy, died. She was replaced by a lookalike but it was more than 30 years before viewers were told.

Editor's choice

• The 100 Best Films of the Decade
• 70 facts you didn't know about Marvel
• The 50 Biggest Movies Of 2010