A quarter of Londoners living in the boroughs of Hackney, Lambeth and Haringey regularly tune into pirate radio stations, according to new research.
Some 40 per cent of listeners told Ofcom, the media watchdog which conducted the study, that illegal radio broadcasts offered more to the community than its commercial and BBC equivalents.
Radio pirates exploit the FM band to illegally broadcast shows, often from make-shift studios.
Ofcom, which takes unlicenced stations off air, said it carried out over one thousand operations that led to 63 convictions last year.
It said that illegal broadcasts can cause havoc with emergency service communication systems as well as interfering with legitimate radio stations.
The research also found that two-thirds of people switch off their radio, or tune in to a different station when interference occurs.
The regulator's chief executive Ed Richards said: "Ofcom's field force team works very hard to keep the radio spectrum free from interference for licensed users.
"However, we recognise that there is demand for content provided by illegal broadcasters in some areas of the country. This research will help shape our thinking on how to tackle this serious issue in the future." ®