Ofcom has fined GMTV £2 million over misconduct in its viewer competitions.

The fine is the largest imposed against a broadcaster by the watchdog.

The competition picked finalists before phone lines had closed, meaning many people who entered had no chance of winning.

The fine comes after GMTV’s competition phone line provider, Opera Telecom Ltd, was told to pay £250,000 by premium rate phone line regulator Icstis.

Picking potential winners early came at a cost of some £20 million to callers. At least 18 million viewers were charged for entering the GMTV phone-in competition with no chance of winning over nearly a four-year period, spending on average more than £1 per call.

GMTV, which has suspended its premium rate competitions, was found to be in breach of the Broadcasting Code on the fair conduct of competitions. Ofcom said the fine related to a period spanning more than three years between August 2003 and February 2007.

GMTV issued a statement saying it took full responsibility. “As soon as we became aware of the problems, we took all premium rate services off air and in July launched a series of comprehensive remedies to recompense our viewers.”

It is offering refunds to disenfranchised entrants and its refund helpline will remain open for the foreseeable future.

It said it had made a £250,000 donation to ChildLine and added: “GMTV has announced a new code for premium rate competitions and we will not reintroduce them into our programmes until we are absolutely sure that the right compliance procedures are in place to enable our viewers to continue to enjoy the competitions knowing they are run fairly and honestly.”