Lord Janner, 86, faces more than 20 allegations of historic abuse at children's homes in Leicestershire

Police were blocked from arresting a high-profile Labour MP suspected of child abuse more than 20 years ago, it was claimed yesterday.

Greville Janner, now Lord Janner, was interviewed by appointment as part of a major inquiry into attacks on boys at Leicestershire care homes in 1991.

The prominent politician and campaigner, who represented Leicester West, was accompanied by his solicitor and did not face charges.

Detectives had taken legal advice from a senior lawyer on the rare and potentially controversial move of arresting the serving politician.

This would have given them the power to search his home and offices, as well as taking his fingerprints and other evidence.

But sources close to the case told The Times that at the last minute the planned arrest was blocked. It is not known by whom.

Arrangements were made instead for Lord Janner to attend a police station by appointment with his solicitor, Sir David Napley.

Leicestershire Police confirmed yesterday that the decision is being re-examined as part of Operation Enamel, which is looking at allegations against Lord Janner and others.

Investigators have consulted Kelvyn Ashby, the officer who led the original case and has since retired.

Lord Janner, now aged 86, faces more than 20 allegations of historic abuse at children’s homes, including claims of rape and sexual assault.

They suspect he used his hobby as a magician – he is a member of the magic circle – to get close to his victims and gain their trust.

One man said he was seven-years-old when the politician visited his care home and left him ‘scarred for life’ by sexually assaulting him.

But in an unusual move, police have not interviewed Lord Janner under caution or arrested him over the damaging allegations.

This is despite searching his home in Golders Green, North London, and Parliamentary office during the course of their nine month inquiry.

It is believed that the Labour peer’s poor health, he suffers advanced dementia, has prevented officers from speaking to him.

A partial file of evidence has been sent to the Crown Prosecution Service (CPS), which is providing the police with ‘investigative advice’.

Yet, some fear Lord Janner’s rapidly failing health could lead to him escaping prosecution. He has strongly denied the allegations against him in the past.

It will ultimately be for the CPS to decide whether there is enough evidence and it is in the public interest to put him on trial.

In 1991, the MP received all-party support when he told the House of Commons that there was ‘not a shred of truth’ in the allegations made against him.

Lord Janner has not registered his attendance at the House of Lords since police raided his £600,000 North London apartment last December.

Lord Janner chairs the Holocaust Educational Trust and is vice-president of the World Jewish Congress

The investigation into Lord Janner and others is one of dozens of historic abuse inquiries taking place across Britain.

Chief constables are so concerned that they have brought together a nationwide group to oversee cases involving ‘persons of public prominence’.

Lord Janner, who represented Leicester North West and then Leicester West for 27 years, was made a life peer on his retirement from Parliament in 1997.

The father-of-three, whose wife of more than 40 years died in 1996, became a barrister in 1954 and was appointed a QC in 1971.

He is associated with a number of Jewish organisations, having served as president of the Board of Deputies of British Jews from 1978 to 1984.

He chairs the Holocaust Educational Trust and is vice-president of the World Jewish Congress.

The Labour peer is described on his website as ‘a key international figure in efforts to seek compensation and restitution for Holocaust victims.’

A Leicestershire police spokesman said it is ‘investigating several complaints in relation to Operation Enamel — it is an inquiry into allegations of criminal conduct and all appropriate lines of inquiry will be progressed.’