Producers defend 'Idol' credibility

Producers have denied that American Idol's credibility has been damaged by a blunder from Paula Abdul.

The judge mistakenly gave feedback on two performances from contestant Jason Castro when he had only sung once on the show.

After making the error, Abdul initially claimed that she had just mixed up her notes. However, she revealed on Wednesday during a radio interview that she had actually seen Castro perform his second song in rehearsals.

Commentators have argued that the mistake undermines the show's premise that the singers' fates rest on their live performances. Others have questioned whether the judges actually have their comments scripted.

Responding to criticism, executive producer Cecile Frot-Coutaz said: "The judges have always acknowledged they occasionally watch rehearsals, but in the end they only comment on what happens in the live show."

Earlier this year a report in The Independent revealed that judges Simon Cowell and Randy Jackson watched rehearsals to help them produce comments for the live show.

The show's host Ryan Seacrest admitted on his KIIS-FM radio show that it was a last minute decision from producer Nigel Lythgoe that confused Abdul.

Lythgoe told Seacrest during the live show that he should ask the judges for comments after the first round of songs, rather than after a second performance.