By Nils Blythe Business correspondent, BBC News

Michael Grade, the chairman of ITV, has been in broadcasting for most of his working life.

Ant and Dec have been caught up in the controversy

Today he said he had "never been involved in anything as grisly as this". So what was he so concerned about?

The answer is contained in a report which he commissioned from the accountants Deloitte in early March. He asked the firm to look back at the use of premium rate phone lines by ITV in recent years.

What the report uncovered was that viewers had paid �7.8 million pounds to make calls to premium rate lines for competitions which had already closed.

Irregularities

The shows involved were some of ITV's most popular entertainment programmes, such as The X Factor, I'm a Celebrity... Get Me Out of Here! and Dancing on Ice.

The report also found editorial failings at shows including Ant and Dec's Saturday Night Takeaway. These involved producers manipulating the outcome of competitions which were supposed to be based on viewers' votes.

These revelations are serious for ITV because it's a trusted brand Steve Barnett, media professor, Westminster University

Although failings at programmes presented by Ant and Dec were highlighted by the investigation, Michael Grade said he believed Ant and Dec were not personally involved in the deception.

The presenters themselves have expressed concern over irregularities of which they said they had no knowledge.

No ITV personnel are being asked to resign over the shortcomings which the report has uncovered.

This contrasts with the BBC, where a senior producer was sacked after a Blue Peter cat was not given the name which won most viewers' votes.

As far as Michael Grade is concerned, it is "business as usual" for the commercial broadcaster.

The report will not draw a line under ITV's problems, however.

So has top-rated talent search show The X Factor

Broadcasting watchdog Ofcom is already investigating three ITV quiz programmes - and it is a watchdog with teeth.

Ofcom recently imposed a �2m fine on GMTV for making millions of pounds out of premium rate calls to competitions which had already closed.

But the biggest blow to ITV will be the loss of trust from audiences.

Steve Barnett, media professor at Westminster University: "I think these revelations are serious for ITV because it's a trusted brand."