The Church of England said it had passed an allegation about Leo Abse to Operation Fernbridge, a Metropolitan Police inquiry.
The Sunday Times reported that Mr Abse, who died in 2008 aged 91, was being investigated by police on suspicion of child abuse.
The newspaper said documents from South Wales Police revealed that claims against the long-serving politician were being examined by another force.
South Wales Police had no information about the story, and Scotland Yard would not confirm or deny whether it was involved.
The newspaper said the Church of England had passed Mr Abse’s name to detectives from Fernbridge, a Metropolitan Police inquiry into an alleged Westminster VIP paedophile network.
A Church of England spokesman said: “An allegation was made to a priest, who passed it on to us, and we passed it on to Fernbridge.”
Mr Abse was MP for Pontypool from 1958 to 1983, and then Torfaen from 1983 to 1987.
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