Media regulator Ofcom has launched a major inquiry into premium rate TV phone-ins. 

Richard Ayre, non-executive member of Ofcom's content board and former BBC News chief, will lead the inquiry and hopes to report by early summer. 

Broadcasters, producers and network operators are expected to be questioned in an attempt to establish why the sector is so vulnerable to breaches. Ayre and his team will also recommend new measures to protect consumers.

Weeks of controversy over voting lines and competitions have seen most UK TV channels come under fire.

Allegations have surfaced about programmes as diverse as Blue Peter and The X Factor, while Vodafone revealed this week that 11,500 text votes for ITV's Dancing On Ice final were not counted. 

Ofcom chief executive Ed Richards said in a statement: "Widespread concern about the use of premium rate telephone lines by broadcasters has raised serious questions about trust between broadcasters and viewers.

"Ofcom has launched a number of individual investigations since the start of the year. However it is clear that a broader set of issues needs to be examined as a matter of priority."

Premium-rate phone watchdog Icstis has already launched its own investigation, and plans to introduce licensing for phone-vote companies.