The dog involved had been returned to its owner just days after it was determined the animal was not a banned breed under the Dangerous Dogs Act.
At 9.48 on Monday August 15, 2016, police received a call reporting that a man in his fifties had been attacked by a dog in the Sheepbridge area of Huddersfield.
Officers attended at the scene and found a 52-year old man with serious injuries.
The man was treated by paramedics and taken to Huddersfield Royal Infirmary with potentially life threatening injuries. He was pronounced deceased at 9pm.
Detective Chief Inspector Mark Swift of the Homicide and Major Enquiry Team who is leading the investigation, said: "Clearly our thoughts go out to the family at this tragic time. They are understandably devastated by what has happened and are being supported by specially trained officers.
"Our investigation is continuing. We believe that the victim was out with his own dog at the time of the attack near to his home address on Riddings Road. His dog, a Yorkshire Terrier was also injured during the incident and received emergency veterinary care."
The suspect dog was detained in to kennels by police.
In June this year, a dog warden visited the address following concerns from members of the public about the dog. A referral to police was made following concerns the dog may be a dangerous breed.
As a result, the same dog was seized by police and following a screening, it was determined the animal was not a banned breed under the Dangerous Dogs Act. The dog was returned to its owner on August 8.
Following yesterday's incident, A 29-year-old man, who is the owner of the dog has been arrested in connection with the incident and has been released on police bail pending further enquiries.
A referral is being made to the Independent Police Complaints Commission.