The Birmingham telecoms firm at the centre of the GMTV phone-in scandal was fined a record £250,000 yesterday - and faces the possibility of a £20 million payout.

Opera Telecom Ltd, based in Brindleyplace, had shown a "reckless disregard" for the interests of callers, the premium rate services regulator Icstis said as it imposed the largest fine in its 21-year history.

The company organised competitions for GMTV over a period of nearly four years in which at least 18 million viewers were charged, on average, more than £1 a call for entering when they had "no chance of winning".

Opera Telecom, whose turnover tops £100 million and whose owner Gary Corbett has an estimated wealth of £75 million, was also ordered by Icstis to fully refund complainants, although this has been suspended for three months pending a review by the regulator of the current refunds scheme.

It also faces a 12-month ban from running any competition services if it fails to undergo an independent evaluation and make changes to address "systemic failures within the company".

GMTV was hit by the scandal last April, when "irregularities" in the running of its phone-in competitions were first discovered. It led to two of its senior staff resigning - managing director Paul Corley and Kate Fleming, the broadcaster's controller of enterprises who was in charge of premium rate competitions.

It was one of a series of scandals involving viewer deception that have rocked the TV industry this year and in a scathing judgment George Kidd, Icstis's chief executive, said the record fine should send a clear message to competition phone-line operators.

"The consumer harm caused was aggravated by the sheer number of callers who paid to enter the competition but had no chance of winning, the huge amount of revenue that was unfairly generated from these callers, the length of time over which the practice had been going on and the extensive damage caused to the public trust in phone-in competitions," he said.

Ofcom is investigating GMTV's role and will report on its findings "in due course".

Opera Telecom was founded by 46-year-old Mr Corbett in 2000 as a global provider of mobile phone messaging, billing and campaign services. Named the UK's fastest growing private company in 2004, it employs about 120 people and made a £6 million profit in the last financial year.

Mr Corbett, who is at number 39 on The Birmingham Post Midland Rich List, could not be contacted yesterday.

In a statement the company said: "Opera Telecom continues to apologise unreservedly for the occurrence of these errors and has worked diligently with GMTV to put in place remedies following its own and GMTV's investigations.

"Opera Telecom fully accepts the adjudication of Icstis as fair and equitable and is working closely with Icstis to ensure that it remains compliant with all regulations and recommendations moving forward.

"A third party has been identified and will independently verify Opera Telecom's full compliance, its compliance culture, policies and governance arrangements.

"Opera Telecom has been through a full and thorough disclosure to Icstis of all systems and records regarding the GMTV competitions. Icstis has been made fully aware of the remedies, new processes and procedures now in place. Opera Telecom has publicly stated on many occasions both its remedial action that has been taken and the significant contribution towards the costs of the remedies announced by GMTV."

Jonnie Turpie, director of digital media at Maverick Television, based in Digbeth, Birmingham, said all broadcasters had to work to restore public confidence.

"This obviously still remains a very serious issue for all concerned: the producers, broadcasters and viewers. Concern about the recent spate of these phone-in issues have affected public's trust in television, and we take that very seriously. We, and I mean all broadcasters, must make sure we restore the viewers' faith in the medium."