The Home Secretary has ordered an inquiry into why the murderer of City banker John Monckton was let out on probation, despite a history of violent crime.

Damien Hanson, 24, killed the father-of-two just three months after being released half way through a 12-year sentence for attempted murder.

Yesterday Hanson's accomplice, Elliot White, was cleared of attempting to murder Mr Monckton's wife, Homeyra. But an Old Bailey jury convicted him of wounding with intent and the manslaughter of Mr Monckton.

The 49-year-old Legal and General bonds director was stabbed to death when the two robbers forced their way into his multi-million pound Chelsea home on 24 November last year.

His wife nearly died from two stab wounds in the back as the pair made off with jewellery worth about £4,000.

Hanson was convicted of the murder, attempted murder and robbery last week. He had a string of earlier convictions and had been out of jail for only a few months since age 14.

'Serious questions'

Home Secretary Charles Clarke said Mr Monckton's "tragic death" raised "a number of serious questions" about why Hanson and White was released from prison and how they were supervised.

The head of the probation service, Andrew Bridges, will conduct "an urgent investigation" due to finish early next year, he added.

He will look into "case management and risk assessment" of the two criminals, and "whether there are wider implications" for other violent offenders.

The systems in place must "minimise the risk to the public", Mr Clarke said.

An official assessment has calculated Hanson was 91% likely to commit another violent crime. Yet he was set free from jail last August and managed at the lowest risk level.

London Probation is now implementing a "root and branch overhaul of the way it manages offenders in the community", it said in a statement.

It added that it took its responsibility to the public "very seriously". But, "sadly there is no such thing as a 'zero risk'."

The service also expressed its sympathy to Mrs Monckton, her family and "all those affected by this horrific offence".

White and Hanson are due to be sentenced next February.