ATHENS: A helicopter has swooped on a prison courtyard as armed men on board fired at guards and lowered a rope to help a convicted killer make his fourth attempt to escape from a Greek prison.

But the plot was foiled when the prisoner was shot and the helicopter was forced to land in the prison's car park.

Brazen ... the helicopter jailbreak was Panagiotis Vlastos's fourth escape attempt. Credit:The Age

Authorities say the chartered helicopter – carrying two armed passengers, a pilot and a technician – first tried to rip off the chicken-wire fence surrounding Trikala prison with a hook dangling from a rope.

When that didn't work, a rope was lowered to whisk away Panagiotis Vlastos, a convicted murderer and racketeer.