• Stop Huntingdon Animal Cruelty activists get up to six years • Judge says six conspirators are not 'martyrs for a noble cause'

This article is more than 9 years old

This article is more than 9 years old

Five animal rights activists who waged a relentless campaign of "violence and terror" against companies and individuals linked to Huntingdon Life Sciences were jailed today.

The campaign involved posting hoax bombs to homes and offices, making threats of violence, daubing abusive graffiti on property and sending used tampons in the post.

Sarah Whitehead, 53, Nicole Vosper, 22, Thomas Harris, 27, Jason Mullan, 32, and Nicola Tapping, 29, were all members of Stop Huntingdon Animal Cruelty (Shac). They were given prison sentences of between 15 months and six years at Winchester crown court.

A sixth member of the conspiracy, Alfie Fitzpatrick, at 21 the youngest member of the group, received a 12-month sentence suspended for two years.

Sentencing, the Recorder of Winchester, Judge Keith Cutler, said the campaign had been "synonymous with intimidation, violence and terror".

"The action was taken in order to distress and terrify, and in that you were successful," he told them.

The court heard the group targeted companies which supplied Huntingdon Life Sciences (HLS), of Cambridge, with the aim of closing the firm's animal testing lab. Some company directors had leaflets distributed near their homes falsely telling neighbours they were convicted paedophiles and others received tamponsin the post with messages saying the blood was HIV positive.

The activists daubed words such as puppy killer, murderer and scum on the houses, cars and nearby roads of those they targeted. The abuse would only stop when the company issued a capitulation statement on the Shac website and cut links with the lab.

The six were part of a larger conspiracy involving the founder members of Shac, Gregg and Natasha Avery and Heather Nicholson, who used the organisation as a front to intimidate companies under badges such as the Animal Liberation Front or the Animal Rights Militia.

The judge said the lawful activities of Shac were a "thin veneer" for its real purpose of intimidation. Other members of Shac, including the Averys and Nicholson, were jailed in January 2009 for blackmailing companies linked to HLS.

Cutler cited the sentencing judge in that case when he said: "I expect you will be seen by some as martyrs for a noble cause but that would be wholly misplaced. You are not going to prison for expressing your beliefs. You are going to prison because you have committed a serious criminal offence."

Whitehead, of Littlehampton, West Sussex; Vosper, of Newquay, Cornwall; and Harris, of Ringwood, Hampshire, admitted conspiracy to blackmail companies and suppliers linked to HLS between 2001 and 2008.

Jailing Whitehead, who was called "Mumsy" by the others, for six years, Cutler said she led the younger members on and corrupted them. She had carried out up to five direct attacks in a night. A "long-term campaigner and trusted insider" within the conspiracy, she had not shown remorse and would be likely to offend again.

Harris had taken over the running of Shac after others were arrested in 2007 and was said to have been fully aware of what others were doing. He was jailed for four years. Vosper received a three-and-a-half-year sentence.

Mullan, of north London; Tapping, of Ringwood; and Fitzpatrick, of Solihull, West Midlands, all admitted conspiracy to harm HLS from 2005 to 2008 under the Serious Organised Crime and Police Act 2005 by interfering with companies supplying them.

Mullan was sentenced to three years and Tapping to 15 months. Whitehead also received a 10-year antisocial behaviour order banning her from taking part in animal rights activities. The others received five-year asbos on the same terms.

Detective chief inspector Andy Robbins of Kent police, who led the £4m operation to catch the gang, described the sentences as a "fitting reflection of the systematic and relentless intimidation of individuals and their employers, carried out by a small group of criminals".