NORTH-EAST shareholders of a controversial animal testing company were placed on alert last night after its managing director was beaten up by baseball bat wielding thugs.

Brian Cass, boss of Huntingdon Life Sciences, was left with a gash to his head and bruising to his body following the attack at his home in Cambridgeshire.

It has fuelled fears over the safety of staff and shareholders of the company.

The Northern Echo reported yesterday how a shareholder in Darlington, County Durham, had been targeted by animal rights protestors in a bid to force her to sell her shares.

Last night, Cambridgeshire Police were urging anyone in the North-East connected with HLS to be "extra vigilant".

The company has scores of shareholders in North Yorkshire, County Durham, Cleveland, and Tyne and Wear.

Spokeswoman Catherine Feast said: "People should be extra vigilant and think about their personal safety.

"Speak to your local police force if you have a particular concern, as we cannot say with a 100 per cent guarantee that nothing will happen to you."

Police said they would be making "every effort" to track down the three balaclava-clad criminals who ambushed Mr Cass on Thursday night.

They sprayed a passer-by who went to help with CS spray before fleeing across fields in the London Road area of St Ives.

Mr Cass said: ''I am not going to give in to these intimidating tactics, even if they do extend into violence.

''There are people who pretend to be concerned about animals but then go and attack someone in this sort of manner. It is totally hypocritical and cowardly.''

Home Secretary Jack Straw has announced that the law will be changed to give police extra powers to stop protests outside the homes of animal lab workers and shareholders.

It would also allow harsher punishments for sending hate mail.

HLS became a focus for anti-vivisectionists after a Channel 4 documentary showed footage of workers beating beagles inside the plant.

Protests have ranged from violent attacks on workers to peaceful demonstrations.

The campaign to close it down has been spearheaded by umbrella group, Stop Huntingdon Animal Cruelty (SHAC).

Both SHAC and the Animal Liberation Front have denied any responsibility for the attack on Mr Cass.

Natasha Taylor, of SHAC, said: "This is not connected to our campaign and we would unreservedly condemn any acts of violence towards people or animals."