Tougher laws could be imposed on TV channels that exploit viewers with premium-rate phone-ins, Culture Secretary Tessa Jowell has warned.
Tessa Jowell said broadcasters must not lose the confidence of viewers
She told The Times newspaper media organisations should never forget the trust people have in them.
Ms Jowell said she would wait to see what action was taken by regulators Ofcom and Icstis before deciding whether extra powers were needed.
A number of premium rate TV phone-ins are currently under investigation.
Premium rate phone watchdog Icstis has launched formal investigations into Channel 4's Richard and Judy, the BBC's Saturday Kitchen and ITV's X Factor.
Ms Jowell told the newspaper: "My message to the broadcasters is that they must never forget the level of trust that people hold in public service broadcasters and you lose that trust and confidence at your peril.
"So any activity that exploits people - which extracts from them more money than they intend to spend - I think has got to be clamped down on very hard."
It has also emerged that 11,500 text votes were not counted during the final of another ITV programme, Dancing on Ice.
All the texts are being refunded and ITV said the missing texts represented less than 1% of the votes cast.
The channel said it would not have changed the result of the competition, which was won by former England rugby player Kyran Bracken.
Broadcaster Five has suspended all programming involving premium rate telephone services after admitting some of its competition winners were faked.
Meanwhile, BBC children's show Blue Peter apologised when it emerged a member of the production team asked a girl visiting the studio to pose as the winning contestant in a phone-in competition because of a "technical problem".