A MAN of 70 yesterday became the first private investor in a controversial animal testing laboratory to be targeted at home by activists intent on shaming shareholders into selling their stakes. Four members of the Group With No Name appeared outside David Braybrook's home in Huntingdon, Cambs, at midday. They had tracked him down through shareholder records at Companies House. The protesters said they would maintain a round-the clock vigil until Mr Braybrook sold his estimated 20,000 shares, worth about £2,700, in Huntingdon Life Sciences.

The group sent a letter to all 1,700 shareholders last month warning them to sell their stakes or face public humiliation for "investing in cruelty". Mr Braybrook, who bought his shares five years ago, said yesterday that he would not be intimidated into selling his shares. He said: "They want me to sell my shares so they can bring the company down but I don't want to do that at the moment. I feel I have the freedom to buy and sell shares."

The protest has been peaceful but Mr Braybrook was concerned that "there might be extremists out there". He also called for tighter regulations at Companies House to protect the identity of shareholders.

HLS runs Europe's largest animal testing laboratory at Woolley near Huntingdon. It became the focus of animal rights campaigns following a Channel 4 documentary three years ago which disclosed that laboratory workers beat dogs. The company yesterday condemned the decision to target shareholders as "outrageous". Dozens of shareholders contacted police after receiving the letters, fearing attack.

The Group With No Name is led by Niel Hansen, 34, who served a jail sentence for sending a hoax bomb to a pregnant woman. It began targeting HLS's institutional investors last November and secured a publicity coup in February when Phillips and Drew, the fund management group, sold its 11 per cent stake in the laboratory after allegedly receiving death threats and hate mail.

Earlier this year, the Labour Party admitted its staff pension fund also held a stake in HLS but said it would sell its shares.

The Group With No Name adopted its title after the British Union for the Abolition of Vivisection (BUAV) obtained a High Court injunction last month ordering it to change its name from BUAV Reform Group. The BUAV attacked the group's tactics yesterday.

Andrew Gay, marketing director of HLS, said: "We've had phone calls from shareholders, particularly elderly people, who say they feel threatened. This is blackmailing people into selling their shares." Although the company's share price has fallen by almost a third to 13.5p following the publicity surrounding the letter campaign, Mr Gay said the animal activists' efforts were futile as shares simply changed hands.

The Group With No Name claims that 250 investors have sold their shares since receiving the letters. A spokesman said: "Many were disgusted at our revelations and have sold up. Those who have not have made a conscious and informed decision to invest in cruelty and we will make sure they are named and shamed."