By ITV Deputy Political Editor Chris Ship

The Home Office investigation did not interview him about his claims.

But today, we did.

Tim Hulbert has not spoken publicly for nearly 35 years about what he witnessed in his government department - but today he spoke to ITV News.

More: Profile of Baroness Butler-Sloss, the family law expert who will lead the sex abuse inquiry

Mr Hulbert is the former civil servant at the Home Office who says he raised concerns with his manager about a Government grant for the notorious group, the Paedophile Information Exchange.

During the first year of the Thatcher administration, Mr Hulbert became aware of a request to renew a grant for PIE.

He is unclear how he found out - he claims he was both tipped off and saw paperwork relating to a grant for PIE - but says he is absolutely certain he had a meeting about it in the office of his line manager.

Both Mr Hulbert and his superior, Clifford Hindley, worked in the Voluntary Services Unit of the Home Office which approved grants to various organisations.

Mr Hindley, however, ordered that the grant be paid.

Tim Hulbert says his superior told him to back off because renewal grants didn't require ministerial approval (suggesting it had been paid before).

In an interview at his home today, Mr Hulbert also says he was told that the payment was made on the orders of the Metropolitan Police's Special Branch.

A statement from the Metropolitan Police to ITV News said:

"The Metropolitan Police Service will fully co-operate with the Home Office inquiry led by Peter Wanless, and provide detail of relevant information.

"Whilst this is ongoing it would be inappropriate to comment further."

Mr Hulbert's recollections suggest that payments to PIE were being made by both the Labour government of James Callaghan and the Conservative administration of Margaret Thatcher.

He wasn't told why Special Branch wanted the payment to PIE to continue.

It was made clear to Mr Hulbert, however, that he should not take the matter any further.

The whistleblower has given a statement to police investigating historic allegations of abuse - but Mr Hulbert has never before given an interview to a reporter.

Labour's former prime minister James Callaghan and the former Conservative leader Margaret Thatcher. Credit: PA

He now asks if the paper trail showing grants to PIE was among the 114 files that the Home Office admits have been lost or intentionally destroyed.

A Home Office investigation last year looked at Mr Hulbert's claims but found no evidence to support them.

The investigator was given a written statement by Mr Hulbert but surprisingly the principle witness was never interviewed about his claims.

A major inquiry has been ordered into an alleged cover-up of historic child sex abuse by leading politicians at Westminster. Credit: PA

The Home Office stands by its investigation but as part of its review will look at this again.

A Home Office spokesperson said:

"The Government is absolutely committed to tackling child abuse and that is why the Home Secretary has announced an over-arching inquiry to consider whether public bodies and other institutions have taken seriously their duty of care to protect children from sexual abuse.

“Earlier this week the Home Office published the final report of an independent investigation into alleged funding of the Paedophile Information Exchange (PIE) in the 1970s. It found no evidence that the Home Office provided direct funding to PIE.

"The report did identify that the Home Office had provided funding to two organisations with connections to PIE but there was no evidence to conclude that this funding was used indirectly to support the work of PIE.”