A Darlington woman has been targeted by an animal rights group intent on closing down a research laboratory.

Leaflets were posted through the letter boxes of everyone living in Thornbury Rise, pinpointing her by name and address as someone who holds shares in Huntingdon Life Sciences.

It points out that the laboratory experiments on cats, dogs, monkeys, rabbits and guinea pigs and urges: "Tell them what you think of their investment in animal cruelty.

It shows emotive pictures of animals at a laboratory, adding: "How would you feel if they got hold of one of your pets?"

A neighbour was the first to show the shocked woman the leaflet, and she called in the police.

Insp Graham Hill of Darlington police said distributing leaflets which caused alarm, harassment or distress was an offence.

He said there would be an investigation.

The woman said she was a shareholder, and also an animal lover. She had some sympathy with the views of the organisation Stop Huntindon Animal Cruelty (SHAC) which sent out the leaflet.

But she felt their views had to be weighed in the balance with the fact the research centre could help people live and have a better life.

The leaflet gives a SHAC web site containing a list of shareholders with addresses. There are another four in County Durham.

Mr Jim Baxter, a spokesman for Huntingdon Life Sciences, whose name appears on the web site, said the company had informed shareholders that their names were appearing on the internet and had given them advice about security.

The pharmaceutical industry had been pressurising the government to allow shareholders to keep their names off company registers. This had resulted in an announcement on Wednesday by the Home Secretary, Mr Jack Straw, about tightening up the law regarding sending hate mail.

"We fully support the right of people to protest peacefully, but are against people being targeted like this," he added.

SHAC spokeswoman Ms Heather James said the organisation had been targeting shareholders for a long time. They felt justified in sanctioning the distribution of leaflets targeting those who had shares in the research laboratory. "We are just giving people information," she added. "Shareholders are fully aware of what goes on at that place and we will continue to expose them."

Nobody was allowed into the laboratory, but dogs had had weedkiller forced down their throats while video evidence had proved that puppies had been picked up roughly by the scruff of the neck and shaken.

"All this leaflet does is tell residents that their neighbour has shares in this company," said Ms James. "I would want to know if my neighbour were investing in something like this, the same as people want to be notified about paedophiles moving into an area. I don't see it as being any different.