Police killer Harry Roberts, who was arrested in a flat in Bolton after going on the run after shooting three London policemen in 1966, can seek a judicial review over a failed parole bid.

Roberts, 71, is serving life for the killings in Shepherd's Bush, west London. His 30-year tariff expired nine years ago.

He lost his parole bid last December on the basis of secret evidence.

A judge ruled his case was "of great public interest" and gave him leave to seek a High Court judicial review.

The murder 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.

All three were unarmed and in plain clothes at the time of the attack.

The officers were shot in front of children playing in a street, after they had pulled over a van containing Roberts and two other men following an armed robbery.

Under current rules, Roberts can only be kept in prison if he is still considered dangerous or a risk to the public.

Roberts is being held in a low-security prison near Newton Abbot, Devon.

After committing the murders Roberts fled the capital and a major manhunt was launched. Police in Bolton were warned to be on the lookout after a tip-off from a motorist that Roberts had been seen in the area.

A man answering his description was seen driving a car with London registration plates in Moses Gate.

Roberts was thought to be on his way to visit his wife, who lived in Manchester. He was eventually arrested at a flat in Chorley Old Road.