A XL bully has been found dead inside a cage in a canal in Birmingham, sparking an RSPCA investigation.

The brown XL bully type, an adult unneutered male aged between one and two years old, was found inside a metal cage in the water in Crawford Street in Saltley on Friday, the RSPCA said.

RSPCA officers were called to the scene by police and scanned the dog, who was microchipped as “puppy 8” with contact details for an address in West Bromwich.

When the address was visited by RSPCA officers, the occupants were said to be shocked and confirmed they had had a litter of puppies which they had sold on and did not have any contact details for the new owner.

Inspector Laura Brewerton has launched an investigation into the dog’s suspicious death.

She said: “We currently don’t know the circumstances around this dog’s death but it’s incredibly concerning that he was found shut inside this crate floating in the water and we can’t rule out the possibility that he was thrown into the canal alive and left to drown, which is horrific.

“We’re now investigating this heartbreaking incident and we’d urge anyone who recognises this dog or who saw anything suspicious in this area on Friday – or the days before – to get in touch with us. This can be done anonymously.”

Anyone with information that could help with the investigation should contact the RSPCA appeal line on 0300 123 8018 and leave a message quoting reference 1288402.

Since February 1, it has been a criminal offence to own the XL bully breed in England and Wales without an exemption certificate.

Anyone who owns one of the dogs must have had the animal neutered, have it microchipped and keep it muzzled and on a lead in public, among other restrictions.

In January, the RSPCA said it had seen a series of “heartbreaking” cases of animals being given up or abandoned in the wake of the Government’s move to ban the breed.