By Alex Stevenson
Evidence which could still be held by the police may reveal "a powerful paedophile network linked to parliament and to No 10", Labour MP Tom Watson has alleged.
The opposition backbencher prompted gasps of surprise in the Commons chamber when he raised the allegation in prime minister's questions this lunchtime.
Watson, speaking under protection of parliamentary privilege, said the evidence file used to convict a man called Peter Righton contained "clear evidence of a widespread paedophile ring".
"One of its members boasts of its links to a senior aide of a former prime minister, who says he could smuggle indecent images of children from abroad," the MP said.
"The leads were not followed up but if the file still exists I want to ensure the Metropolitan police secure the evidence, re-examine it and investigate clear intelligence suggesting a powerful paedophile network linked to parliament and to No 10."
Righton was fined £900 after admitting importing and possessing illegal homosexual pornography in 1992. Customs officers had intercepted a book and a magazine at their Dover postal depot in April of that year, the Independent newspaper reported at the time.
David Cameron responded by saying Watson had raised "a very difficult and complex case". He added: "I'm not entirely sure which prime minister he's referring to... I want to see what the government can do to help give him the assurances that he seeks."
Watson's allegations may be linked to a Sunday Times story published this weekend in which former Conservative minister Edwina Currie claimed Margaret Thatcher's former parliamentary private secretary, Peter Morrison, had sex with 16-year-old boys when the age of consent was 21.
Currie drew parallels with revelations about the late Jimmy Savile, whose sexually abusive behaviour has prompted a scandal about the culture at the BBC during the 1960s, 70s and 80s. Morrison died in 1995 and was described by Currie in her 2002 memoir as a "noted pederast".
"Even if Morrison was behaving in a criminal fashion, getting cases to court would have been difficult particularly if the young witnesses — one might be talking about a 17-year-old — did not want to give evidence," she explained.
"Unless somebody actually made a complaint to the police, perhaps involving violence, the chance of getting a criminal conviction would be very slim."
Watson, who has won plaudits for his unflinching assault on Rupert Murdoch's media empire, was understandably nervous before his appearance in parliament this lunchtime.
Earlier he tweeted: "Hoping to catch the Speaker's eye at #pmq's today. It's been a while. Feeling a bit anxious about it."
By Alex Stevenson