Roberts is now in his late 70s
Police killer Harry Roberts is to be released from prison after more than 45 years.
Roberts was jailed for life for murdering three officers in Shepherd's Bush, west London, in 1966.They were shot in front of children playing in a street after they had pulled over a van containing Roberts and two others, after an armed robbery.
BBC Home Affairs correspondent Danny Shaw said the Parole Board had approved the release.
However, our correspondent said it was not yet clear when this would take place, and it is understood there will be strict conditions.
Devon prison The murders of PC Geoffrey Fox, 41, Sgt Christopher Head, 30, and Det Con David Wombwell, 25, became one of the most infamous crimes of the 1960s. The officers were unarmed and in plain clothes at the time.
The men shot dead were (left to right): PC Geoffrey Fox, 41; Det Con David Wombwell, 25; and Sgt Christopher Head, 30
Roberts, who is in his late 70s, had been held in a low-security prison near Newton Abbot, Devon. A Ministry of Justice (MoJ) spokesperson said it did not comment on individual cases.
An MoJ spokesman said: "The release of life sentence prisoners is directed by the independent Parole Board once they are satisfied they can be safely managed in the community.
"Once released they are subject to strict controls for as long as their risk requires them. If they fail to comply with these conditions they can be immediately returned to prison. Offenders managed through Multi Agency Public Protection Arrangements (Mappa) are monitored and supervised by probation, police and other agencies."