After weeks of controversy, the fall-out from the premium rate TV line phone-ins continues with media regulator Ofcom now launching a major inquiry into the fiasco.

The move follows the announcement last month by premium rate watchdog Icstis to set new rules to make sure that people who take part in participation TV and radio programmes are not ripped off.

Allegations surfaced about programmes, ranging from Blue Peter to chat show Richard and Judy, misleading or overcharging viewers who phoned in to take part in competitions or vote in reality shows.

Ofcom chief executive Ed Richards said that "widespread concern about the use of premium rate telephone lines by broadcasters has raised serious questions about trust between broadcasters and viewers".

The Ofcom enquiry will be lead by Richard Ayre, a non-executive member of Ofcom's content board and former BBC News chief. It will have substantial input from Icstis and examine consumer protection issues and audiences’ attitudes to the use of premium rate telecoms services in television programmes.

The regulator will also look at the compliance and editorial responsibilities of broadcasters, telecoms operators and others involved in these programmes and the effectiveness of these procedures.

Icstis chairman Sir Alistair Graham said he believed the recent problems were more a case of broadcasters being "sloppy" over how they run premium-rate lines rather than an indication of any "conspiracy".

However, under the Ofcom inquiry, 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.

Ofcom chief executive Ed Richards said: “Widespread concern about the use of premium rate telephone lines by broadcasters and editorial standards in those programmes has raised serious questions about trust between broadcasters and viewers.

“Ofcom has been monitoring the issue closely and has launched a number of individual investigations since the start of the year. However, it is clear from the number of cases underway that a broader set of issues need to be examined as a matter of priority.

“This inquiry will seek to establish the root cause of the compliance issues which have emerged over recent weeks, and inform key decisions about protecting consumers.”

It is expected that Ayre will report his findings by early summer.