Cambridgeshire Police initially attended the MBR Acres site in Wyton at 5am on Sunday, June 19 after receiving reports of a burglary.
A group of 25 protestors wearing white overalls had gained access to the facility, which reportedly breeds around 2,000 beagles a year – supplying universities and private laboratories where experiments are conducted for research.
It is claimed protestors holding pink and white signs reading 'end animal testing' refused to leave the site. This comes after singer Will Young handcuffed himself to a gate at MBR Acres in a one-man protest last November.
Officers were called out again at 3.00am on Monday, June 20. There was another break-in, and dogs were taken from the premises.
Twelve people have since been charged with burglary and were due to appear at Cambridge Magistrates’ Court today (Tuesday, June 21). They include Sara Harrison, 52, of Hallowes Court, Dronfield and Callum Goode, 22, of Compton, Ashbourne.
The stolen dogs have yet to be recovered.
Members of the Animal Freedom Movement posted videos and pictures on social media appearing to show beagles inside the facility.
The group wrote on Facebook it wants the MBR Acres facility to be shutdown and for the UK government to end animal testing and the sale of animal-tested products by 2025.
It added that protestors will occupy the site until these demands are met.
Dillon Parsons, spokesperson for the group, has said: "Using animals for testing is not only cruel, inhumane, and barbaric, it is completely unnecessary.
"There is no need for nearly 3 million painful and torturous tests on animals in the UK each year when we have technology that is more reliable and efficient.
"The UK claims to be a nation of animal lovers, we demand The Government and MBR show that to be true"
The Animal Freedom Movement said it will hold a demonstration outside the Home Office on June 27.