The widow of a dad-of-three brutally stabbed to death metres from their home has called for an independent investigation into claims police officers were stopped from responding to his killing.

Clare Else, 52, said she had no faith in a Metropolitan Police probe into allegations two police sergeants ordered junior officers not to attend to reports of the attack that killed her husband Andrew.

Mr Else, 52, died after being stabbed more than 200 times by Ephraim Norman in Selsdon Park Road, South Croydon, in April last year.

Mrs Else, of Woodpecker Mount, Pixton Way, in Forestdale, was kept in the dark about the investigation into police sergeants Kirsten Treasure and Jason Chapman.

LAST WEEK: 'Insufficient evidence' to prosecute police sergeants who allegedly stopped officers responding to fatal stabbing

After learning the Crown Prosecution Service (CPS) had concluded there was insufficient evidence to prosecute the pair, she said: "That's unbelievable. I don't see how they can make that decision so soon. They have been investigating it since March."

She added: "The police failed to do their duty. My husband was probably laying there thinking help should arrive shortly."

The Metropolitan Police had passed files on the sergeants to prosecutors to assess whether their actions amounted to wilful neglect of duty. The force's own investigation into the allegations is ongoing and the sergeants have been place on restricted duties.

But Mrs Else said: "They are doing an investigation on themselves. How can you trust what that is? You can't, can you? 

"I want an external investigation and I would like somebody to call me to tell me that. To me it just feels like there is a cover-up.

"They can't change the result with Andrew, but what about the rest of us that are out there expecting them to turn up and they don't? How is that supposed to give the rest of us comfort and make us feel safe?"

Sgts Treasure and Chapman are alleged to have told junior officers at Addington station, just 700m from the spot where Mr Else was attacked, not to respond to the call because they had other duties to attend to.

Emergency response officers from Croydon station, nearly four miles away, were instead first on the scene.

But a CPS spokesman confirmed on Friday: "Following a thorough review of the evidence in accordance with the Code for Crown Prosecutors, we have decided that the evidence is not sufficient for there to be a realistic prospect of proving that the officers’ actions amounted to a wilful neglect of duty, which is the standard required.

"We have therefore advised that no further action be taken."

Neither the CPS nor the police informed Mrs Else of prosecutors' decision, which she learned about from the Croydon Guardian.

She also learned of the investigation into Sgts Treasure and Chapman from a journalist and did not receive contact from the police until after the story emerged.

Detective Chief Superintendent Alaric Bonthron, from the Met's Directorate of Professional Standards, said earlier this month: "The suggestion that any police officer has in some way failed to do their duty and respond properly to any call for a response must be fully and properly investigated.

"If any officer has failed in their duty it is only right that they are held to account. Every day in London police officers work hard to keep the public safe. Allegations such as these trouble us all."

Norman, 24, who has paranoid schizophrenia, pleaded guilty to manslaughter by reason of diminished responsibility earlier this year over the killing and was ordered to be detained indefinitely at maximum-security hospital Broadmoor.