Met police
File photo: Metropolitan police officer iStock

Police in Britain do not understand the law and let criminals get off free because they do not investigate crimes properly, a former senior prosecutor has claimed.

Nazir Afzal was the chief crown prosecutor for northwest England until 2015 and he helped who prosecute the notorious Rochdale child grooming gang.

He has accused police of "charging cases prematurely" and that officers were vulnerable to political pressure.

Afzal said officers viewed charging people not convicting them as the most important thing and did not understand the rules of disclosure in which evidence including that which weakens the prosecution case needs to be handed over to the defence.

Nazir Afzal
Former Crown prosecutor Nazir Afzal (R) pictured outside Preston Crown Court on June 17, 2013, has said that police officers do not investigate crimes properly Getty Images

He wrote on the Times website that failing to disclose evidence not part of the prosecution case can mean that cases are stopped because it would be unfair to have a trial and so allows guilty defendants to go free.

"Often this is down to poor supervision by senior officers and the quality of investigations," he wrote.

He said officers did not understand how to follow different lines of enquiry and they often went for the easiest option.

"I have seen lazy policing where they rely upon the seizing of cash from offenders instead of prosecuting them under the proceeds of crime money laundering provisions.

"It is lazy because they know they are allowed to keep 50 per cent of the cash that they seize but if they proceeded to prosecute, they would get less than half of that.

"Incrementally, the police are being deskilled and their confidence shaken," he added.

There have been calls by police chiefs for higher pay with Steve White, chairman of the Police Federation, saying that there would be a recruitment crisis if officers did not get a proper pay rise.