'There are a series of claims over a relatively long period of time and not all of them are linked – although in the public’s imagination they may be.
‘We have now had more recently this discussion or these claims about murder and, of course, that makes it even more serious.’
Among the latest allegations are that police may have helped cover up the murder of an eight-year-old boy.
It is claimed he was one of three killed by the network alleged to include former MPs and cabinet ministers.
Detectives are searching through files on at least 200 missing children to try to identify the alleged victims.
A man who claims to have been sexually abused by the group has told police he saw a then-serving Conservative MP murder a boy during a sexual assault in London in around 1980.
He said he witnessed the murder of another boy in front of a former Conservative cabinet minister around one or two years later.
He also alleged that a third boy had been killed.
The Government is still seeking a chairman for its wide-ranging inquiry into the handling of paedophile activity by members of the Establishment after two candidates quit over their links to senior figures from the period.
Shadow Home Secretary Yvette Cooper said yesterday: ‘The latest revelations on historical child abuse are alarming.
‘And the Home Secretary is right that this is likely to be the tip of the iceberg.
‘It is important the inquiry gets under way and that action is taken swiftly to make the system better now so we can protect our children and take what they say about anyone seriously.’
She spoke as it emerged that Labour figures were passed warnings about the Elm Guest House, which was allegedly used by the paedophiles.
A union official wrote to David Blunkett and John Prescott, the then home secretary and deputy prime minister, to warn that it was being used as a brothel.
Mr Blunkett, who replied personally in November 2002 and alerted Home Office staff, yesterday said the tip-off did not include claims of child sex abuse.