Scotland Yard's shambolic investigation into alleged VIP child sex abuse and murder inched closer to collapse last night after a new officer was put in charge.

Detective Superintendent Kenny McDonald, who controversially described a key witness as being 'credible and true', has been replaced as head of Operation Midland.

It was confirmed last night that Det Supt McDonald had been removed from the inquiry as part of a shake-up widely seen in key circles as the 'beginning of the end' for Operation Midland.

The news came as Home Secretary Theresa May distanced herself from the force's Leon Brittan rape inquiry, saying police should tell suspects in a 'timely' way if they have been cleared.

Detective Superintendent Kenny McDonald, who controversially described a key witness as being 'credible and true', has been replaced as head of Operation Midland

Theresa May has distanced herself from the force's Leon Brittan (pictured right) rape inquiry

She made her dissatisfaction clear after it emerged that detectives were told on four occasions there were no grounds to charge the Tory peer after he was accused of rape by a Labour activist with severe mental health problems.

Lord Brittan died in January at 75 without being told he had been cleared.

The restructuring of the Operation Midland team was announced ahead of a hearing tomorrow of the Commons Home Affairs Select Committee, when Yard chief Sir Bernard Hogan-Howe will be quizzed over the unravelling VIP abuse fiasco.

The Met has been under pressure to shelve the investigation since the Mail told last month how detectives had 'grave doubts' about the testimony of a man known as Nick whose allegations of triple murder involving the top tier of the security establishment triggered the probe.

After spending nearly a year on the case, officers have found 'not a shred of credible evidence' to back up claims that a string of senior Establishment figures were responsible for murdering three boys in the Seventies and Eighties.

The restructuring of the Operation Midland team was announced ahead of a hearing tomorrow of the Commons Home Affairs Select Committee, when Yard chief Sir Bernard Hogan-Howe (pictured) will be quizzed over the unravelling VIP abuse fiasco

Earlier, Mrs May piled pressure on Sir Bernard over the refusal of officers to abandon the case against Sir Leon for almost three years

A number of other exposes by this newspaper in recent weeks have cast further doubt on other alleged victims of VIP child sex abuse.

In a statement issued last night, which made no mention of Detective Supt McDonald, the Met said it had 'brought together all the various strands of non-recent child abuse allegations under a newly formed investigation team led by Detective Superintendent Ang Scott'.

Det Supt Scott will run Operation Midland and Operation Fairbank, which began in 2012 to look into claims of child abuse at the Elm Guesthouse in Barnes, South West London, and at other locations.

The statement said: 'As Operations Midland and Fairbank have progressed officers identified a number of people and locations common to both enquiries.

'It is therefore operationally important to have the same officer in charge. This team will also be responsible for the preparatory work to support the Independent Inquiry into Child Sexual Abuse.

'This team will continue to investigate the various operations that are ongoing, including those historical allegations of impropriety by police officers dealing with sexual abuse in the period 1970-2005.'