WASHINGTON (CBS19 NEWS) -- Hundreds of dogs have been rescued from a breeding facility in Virginia that is accused of abusing animals.

However, Senator Mark Warner says there are still thousands of puppies still at the facility, with is run by Envigo.

The facility raises dogs to be used for research purposes.

Envigo has faced more than 70 different incidents in which it has been accused of violating the Animal Welfare Act by mistreating dogs, mainly beagles, at its site.

Warner says nearly 450 dogs have been rescued already from the facility, and the U.S. Department of Justice has taken over the investigation.

“Candidly, we need to hold Envigo to the full extent of the law,” Warner said. “There are close to 3,600 dogs that are still in their custody, and we need to get to the bottom of making sure those dogs, literally these are puppies, are kept safe.”

The DOJ and Envigo filed a joint motion that extends a restraining order on the facility until June 13.

They hope to work out any remaining issues and determine if a settlement is possible.