The boxer whose punches stopped Princess Anne’s kidnapper has told of his outrage after the offender was set free, saying: ‘I should have hit him harder.’

Ronnie ‘The Geezer’ Russell, 77, was speaking of his anger over the release from Broadmoor Hospital of ‘very dangerous’ Ian Ball.

The Daily Mail revealed on Saturday that Ball, also 77, had quietly been freed, despite remaining unrepentant for the March 1974 night when he shot four men on The Mall in London, near Buckingham Palace.

Happy to kill in his quest to hold Princess Anne, then 23, for a £3milllion ransom from the Queen, the loner had not reckoned with 6ft 2in, 17 stone Mr Russell, driving past.

The former boxer was undeterred by Ball’s threats to shoot, and punched him three times over a terrifying few minutes, before police arrived mob-handed and bundled the kidnapper to the ground.