In 1959, Denning was jailed in Germany for distributing pornographic images. Denning's first conviction for
gross indecency and
indecent assault was in 1974 when he was convicted at the
Old Bailey, although he was not imprisoned. called the
Walton Hop. Other participants included
Tam Paton, manager of
the Bay City Rollers (convicted of child sex offences in 1982), and Jonathan King. All became suspects in Surrey Police's
Operation Arundel, an investigation focusing on sex offenders, which ultimately led to convictions against King and Denning. In 1985, he was imprisoned for 18 months for
gross indecency with a child, In 2008, he was extradited from Britain to Slovakia, where he was jailed in October for five years for producing
child pornography. He was re-arrested and bailed out in September of that year. The allegations made against Denning were not part of those relating to
Jimmy Savile. In May 2014, as a result of the investigation, he was charged with 41 sex offences. In August 2014, Denning admitted to 29 of the charges in relation to the offences committed against boys. In November at
Southwark Crown Court, he pleaded guilty to a further eleven charges. In all, he pleaded guilty to 40 sexual offences committed in the period 1967 to 1987 relating to 26 male victims, the youngest of whom was 9 at the time of the offence. In December 2014, Judge Alistair McCreath sentenced him to 13 years in prison. Denning was charged with six offences stemming from the
Operation Ravine investigation on 7 June 2016. On 22 August 2016, Denning pleaded guilty to 21 sex offences between 1969 and 1986, against 11 boys, the youngest of whom was 8. At Southwark Crown Court on 7 October 2016, Judge Alistair McCreath sentenced Denning to another 13 years in prison for these additional offences, running from the day of the court hearing. On 7 December 2017, Denning pleaded not guilty to two counts of indecent assault and one of taking indecent photos of a child between March 1979 and March 1981. His trial was due to start on 11 June 2018, but the charges were dropped on 13 June. ==Death==