The boss of an animal testing laboratory has been attacked by three masked people wielding baseball bats.
Brian Cass, the managing director of Huntingdon Life Sciences, was beaten in a "callous and cowardly" attack.
Detective Inspector Robbie Robertson says the 53-year-old was attacked as he arrived home in St Ives.
Police are in no doubt the attack was linked to the animal experiments carried at HLS.
Two members of the public who tried to help Mr Cass were sprayed with CS gas before the assailants, one of whom is believed to be a woman, fled.