An inquiry into the Home Office's handling of child sex abuse claims in the 1980s has failed to uncover any of the missing documents that prompted the probe, BBC Newsnight has been told.
The inquiry centres on concerns the Home Office did not act on information passed on by Tory MP Geoffrey Dickens.
The inquiry's report is expected to criticise the department's archiving in the 80s and 90s, and dash hopes the so-called "Dickens' dossier" still exists.
The Home Office has refused to comment.
'Lost or destroyed'
The review, led by NSPCC chief executive Peter Wanless, was commissioned by the home secretary in July following criticism of an internal Home Office report into how the claims were dealt with.
That review revealed the Home Office had "lost or destroyed" 114 files and could find no evidence of the information compiled by Mr Dickens - and passed to the then Home Secretary Leon Brittan in 1983.
That information was said to contain the names of MPs and police officers who were suspected of being child abusers.
Now, a source familiar with the Wanless report has told BBC Newsnight: "They have looked inside and behind every single cupboard in the department, and they have been round them twice, and they have not been able to find any of them [the documents]."
MP Simon Danczuk, who, in July, called on Lord Brittan to say what he knew about paedophile allegations passed to him in the 1980s, told the programme: "I am worried Peter Wanless has been set up to fail in many respects.
"I don't think he was given enough time to carry out this investigation. I don't think he was provided with enough support within the Home Office and I am worried he didn't get the technological support.
"I think there are some fairly sophisticated forensic techniques that could have been used to establish what documents were available over a 20-year period and I don't think he has been given the opportunity to get to the documents."
Peter McKelvie, a former child protection manager, whose allegations about child abuse led to a 2012 police investigation, said it should not be an excuse to say the files are lost.
He told Newsnight: "If the file can't be found, I actually personally think that's a little bit of a red herring because there are enough politicians and officials within the Home Office and even within the hierarchies of the three main parties that would be aware of what its content were.
"The information is out there and anyone who tries to deny that is misleading people."
The review is being published as a wider inquiry into historical child sex abuse gets under way despite its chairwoman, Fiona Woolf, resigning following disclosures about her links to Lord Brittan.
The City lawyer's predecessor, Baroness Butler-Sloss, also resigned, similarly over her links with establishment figures.
Elsewhere on Friday, members of the panel have been meeting victims' representatives for a second time.
Some abuse survivors have called for the panel to step down, arguing that the process of appointing its members has not been transparent.
But panel members have indicated that they want to get on with planning the shape and scope of the inquiry.
The BBC's home affairs correspondent Tom Symonds said: "This morning's meeting could result in a confrontation."
On Monday, Mrs May apologised in the Commons after Mrs Woolf stood down.
Making a statement on the wider child abuse inquiry, Mrs May told MPs: "I know that some members of the House have suggested that the government should publish today the Wanless report about the Home Office permanent secretary's investigation into the so-called Dickens' dossier.
"I can tell the House that the Wanless report will be published next week.
"This is because it is about a separate but related matter to the work of the panel inquiry and I want members of the public and the media to have time to scrutinise both this statement and the Wanless review properly."