Police have begun an investigation into historical allegations of child abuse at a south-west London guesthouse.
Operation Fernbridge will examine claims that a 1980s paedophile ring, with links to the then government, abused boys at Elm Guest House, Barnes.
Last year MP Tom Watson called for an investigation into the political links of convicted paedophile Peter Righton.
Righton worked as a consultant to the National Children's Bureau until his arrest in 1992.
A week ago police working for a scoping exercise, Operation Fairbank, took boxes of documents from the London home of Mary Moss, who worked as an advocate for abused children at the now defunct National Association for Young People in Care.
Ms Moss said the documents contained evidence that senior figures from a number of political parties had abused children at Elm Guest House and elsewhere.
There is no suggestion that Ms Moss is herself under investigation.
Elm Guest House is now a private residence and the current occupants are not connected to the allegations.
Operation Fernbridge will be led by the Metropolitan Police Service's Child Abuse Investigation Command.