Humberside Police and the RSPCA have swooped in large numbers at a vets centre in South Killingholme.
They are understood to be carrying out an intelligence-led operation and arrived on site at around 10am on Thursday, March 22.
Around 30 dog rescue vehicles and several Dog Trust ambulances were also in attendance at Four Paws Veterinary Clinic on Habrough Road.
Four Paws Veterinary Clinic has been established for 12 years and its website states the service offers “a range of services for your pets including a low cost veterinary service in a bespoke veterinary clinic”.
It also offers boarding kennels, dog transportation and dog rescue and adoption.
Inspector Tim Harvey at Humberside Police said: “We and our colleagues at the RSPCA are currently carrying out an intel-led operation at an animal rescue organisation in Killingholme.
“At this stage, we cannot confirm any further details, as the investigation is ongoing.”
An RSPCA spokesperson added: “RSPCA officers have accompanied police as a warrant is being executed at a property in Killingholme in Lincolnshire today. Dogs Trust and vets are also present to assist.
“As an investigation is ongoing, we cannot go into any further detail.”
An eyewitness at the scene told Lincolnshire Reporter police and RSPCA officers had been unloading animal cages and arranging paperwork this morning.
“It looks like they are starting to remove some animals and more vans are arriving as we speak.
“Worried members of the public are leaving microchip details and contact details with officers who can’t release the animals.”