TV quiz shows which can charge viewers as much as 75p for phone calls even if they do not get through are a "lottery" not a test of skill, MPs have heard.
Some viewers are said to be running up huge phone bills
The Commons culture committee was told some channels lured players with easy questions and big prizes, without stating only 0.5% of calls get through.
Nick Rust, of Sky Bet, which is calling for stronger guidelines, said phone-in games should count as gambling.
If they were reclassified, they would be "properly regulated", he told MPs.
'Hooked on shows'
The government has warned against a "knee-jerk" reaction to concern about phone-in quizzes.
The MPs are investigating whether the public is being given enough information on the cost of calls, the chances of winning and the size of phone bills.
Martin Le Jeune, BSkyB's head of public affairs, said: "Our concern at the moment is that regulation is not quite keeping pace with these developments."
Shari Vahl, from BBC Radio 4's consumer show You and Yours, said one woman had spent £1,500 in a month on calls.
She also suggested that programmes could get about 200 calls per minute, making the chance of getting through to the studio very small.
But David Brook, co-founder of the production company Optimistic Entertainment, said only a "small minority" of viewers had a problem with spending too much money on calling lines.
"We don't wish to encourage people to make multiple calls," he added.
Phone-ins were "prize-based competitions" with "an element of skill - you have to know the answers to the questions".
However, committee chairman, Tory MP John Whittingdale, said some of the questions were dubious.
He said one programme had asked viewers to name items found in a woman's handbag.
The winning answer, Mr Whittingdale said, to laughter from the committee, was "rawlplugs".
The quiz phone-in industry is monitored by broadcasting watchdog Ofcom and telephone regulator ICSTIS.
Broadcasting minister Shaun Woodward said that, even if some channels were running scams, "it doesn't necessarily follow that they are all doing it".
The government would introduce more regulation if this was deemed "proportional" to the problem, but industry self-regulation would be "quicker, more flexible and more likely to work", he added.
Mr Woodward said that "realistically, when we take part in these programmes, you know that the odds are stacked against you".
He went on: "If they [quiz shows] turn out to be scams they are illegal and, if they are illegal, then they are already on the wrong side of the law."
MPs suggested the quiz shows could put up on-screen warnings for viewers, stating their chance of getting through at the time.
But Jeff Henry, chief executive of ITV's consumer division, said: "If we put up that there is a one in 400 chance of getting through to this line... as soon as we did that - by the time we had - it would be out of date and we would be accused of misleading you."
ICSTIS, the Gambling Commission and Ofcom are already looking at TV quiz show phone-ins.
City of London Police are involved in an on-going fraud probe, the MPs heard.