Dame Eliza Manningham-Buller, who was Director General from 2002-2007, is to be questioned about her relationship with Sir Peter Morrison, who she allegedly reported in the 1980s.

A former head of MI5 is set to be the first spy chief to give evidence before the child sex abuse inquiry over her links with a Conservative MP, it has been claimed.

Dame Eliza Manningham-Buller, who was Director General from 2002-2007, is to be questioned about her relationship with Sir Peter Morrison, who she allegedly reported in the 1980s.

It is claimed her superiors at the time suppressed the information she passed on, according to the Times.

Dame Eliza is expected to give evidence before the inquiry into Child Sexual Abuse (IICA) next week, which is investigating allegations of paedophile activity in Westminster.

She is believed to be the first spy chief to give evidence at a public inquiry in open session and is expected to be asked whether she spoke about the allegations against Morrison with the MP.

In a memo uncovered in 2015, then-Director General Sir Antony Duff is said to have described Morrison’s ‘penchant for small boys’ in a message to Cabinet Secretary Robert Armstrong.

However, the late spy chief then recommended that no action be taken against the Thatcher aide because of the ‘risks of political embarrassment to the government is rather greater than the security danger.’

The letter was part of a cache of files unearthed by the Cabinet Office in 2015 and handed over to an official inquiry into historical abuse allegations.

At the time the Cabinet Office commented that the ‘risk to children is not considered at all.’

She is believed to be the first spy chief to give evidence at a public inquiry in open session and is expected to be asked whether she spoke about the allegations against Morrison (pictured with former Prime Minister Margaret Thatcher)

When the memo was first released, Lord Armstrong refused to name the MP involved and insisted the allegations were just ‘shadows of a rumour’.

He said he believed the decision not to investigate the paedophile claims was ‘correct at the time’.

Lord Armstrong told the Daily Mail in 2015: ‘I thought MI5’s actions were correct at the time. I think they were right to report the rumour, they were right to make what inquiries they could and they were right to come to the conclusion they did.

‘I think if there was evidence it would have been properly examined at the time. I don’t think this is a matter of important people being protected. You can’t pursue inquiries unless you have evidence on which you can base the enquiry. A shadow of a rumour is not enough.’

He said he did not know if Mrs Thatcher was told of the MI5 decision.

Dame Eliza studied English at Lady Margaret Hall, Oxford, and worked as a teacher before joining MI5 in 1974.

She specialised in counter security and

Sir Peter Morrison was first elected as an MP in 1974 and was a close aide of Margaret Thatcher until he stood down in 1992.

Morrison died in 1995, at the age of 51.

An IICSA spokesman told the Times: ‘The inquiry wishes to make clear that the fact certain individuals will be named during this public hearing does not mean that the allegations against them are true. This investigation is not examining the truth or otherwise of individual allegations. The inquiry is simply addressing issues of grave public concern.’