Alison Saunders, chief prosecutor for London, said: "We certainly did not think there was a realistic prospect of conviction against the other three."

A CPS spokesman said in a statement there was "insufficient evidence" to provide a realistic prospect of conviction for rape.

On 27 January 2010, the Crown Prosecution Service dropped all charges against the Space Hijackers because there was "not enough evidence to provide a realistic prospect of conviction".

A case will only be prosecuted, first, if there is sufficient evidence to provide a realistic prospect of conviction against each defendant on each charge, and second, if it is in the public interest to prosecute.

A spokesperson for the CPS said that the prosecution was unable to provide sufficient evidence to contradict this new evidence and therefore took the decision that there was no longer a realistic prospect of conviction.

On 20 June 2000 the CPS issued a press release stating "It is our decision that prosecutions are not possible at this time as there is insufficient evidence for a realistic prospect of conviction against any officer".

'The Director has decided that in the light of the learned judge's ruling in the first trial, the second trial should not proceed because there is no longer a realistic prospect of convictions,' the CPS anounced yesterday.

They had been summoned to appear at Cardiff Magistrates Court on 14 January 2008, but the case against Henson was later dropped by the Crown Prosecution Service due to insufficient evidence to provide a realistic prospect of conviction.

"The decision was taken in accordance with the Code for Crown Prosecutors and after careful consideration of all the evidence I am satisfied there is sufficient evidence for a realistic prospect of conviction and it is in the public interest to prosecute this case.

Since the inauguration of the Crown Prosecution Service in 1986, the proportion of weaker prosecution cases has declined as a result of the CPS' review function which requires a "realistic prospect of conviction" before a prosecution can be commenced or continued.

The Serious Fraud Office and the Director of Public Prosecutions said they were "now satisfied that all lines of inquiry have been pursued and that the evidence available is insufficient to afford a realistic prospect of conviction for any criminal offense relating to any matter of substance raised in the report."

In a statement to the court, the prosecutor said the government no longer believed that there was a "realistic prospect of conviction," even though Ms. Gun was prepared to admit that she had willfully violated Britain's Official Secrets Act by leaking a top secret e-mail message to The London Observer.

"After the most careful consideration, I have concluded that there is insufficient evidence to provide a realistic prospect of conviction against any individual police officer," Mr. O'Doherty said in a statement, explaining that the two officers who fired a total of seven shots at Mr. Menezes genuinely believed he was a terrorist.