As the UK's latest historical sex abuse trial opens in northern England, a whistleblower on Rotherham's grooming gangs says the dozens of men convicted so far are just the "tip of the iceberg". "Of course, it's still going on, but I think it's going on across every town, every city in the UK," says Jayne Senior, who worked to expose the scandal. Thousands of girls and young women are believed to have been abused over several decades in towns across England, although the toral number of victims is unknown. Gangs of men, often from Pakistani backgrounds, targeted mostly white girls from disadvantaged backgrounds, some of whom lived in children's homes. The gangs operated in several English towns and cities, notably in Rotherham and Rochdale in the north, but also in Oxford and Bristol, for almost four decades. IMAGES AND SOUNDBITES