Officers from West Yorkshire Police took the Staffordshire Bull Terrier-Labrador cross named Alex in June after neighbour David Ellam raised concerns. 

But they gave it the `all-clear` after a screening, ruling it was not a banned breed under the Dangerous Dogs Act. 

The dog was returned to its owner on August 8. And on Monday (August 15), the bitch savaged Mr Ellam, 52, as he tried to shield his Yorkshire terrier on his doorstep in Huddersfield. 

Frantic bystanders threw the leisure centre worker a bread knife to protect himself but he refused to stab the animal. 

Mr Ellam suffered serious injuries to his head, arms and leg and died later in Huddersfield Royal Infirmary. 

A 29-year-old man, who is the owner of the dog, has been arrested in connection with the fatal attack and has been released on police bail pending further inquiries.  

The force has referred itself to the Independent Police Complaints Commission as a result of its previous contact with the animal. 

It confirmed that in October 2012 a dog control order had been issued to Kirklees Council against the dog and its owner, putting conditions in place for the management of the animal. The order remains in place to this day. 

Mr Ellam was trying to shield his terrier as the attack dog clamped its jaws around his head, according to witnesses. 

One witness, who asked not to be named, said: “As soon as I saw the dog attacking him I ran inside and called the owner, who told me he would be there in a minute. 

“I went back outside and the victim was shouting. By that time his kneecap was completely gone and blood was everywhere.  

“The dog latched onto the guy’s head and had him in a vice. The dog then started ragging his head from side to side.  

“Someone else got out a hosepipe and used that at the dog – but it still wouldn’t let go and kept on dragging the man closer to its kennel.”  

The witness added: “There were tensions between the victim and dog owner anyway – because of the victim’s small dog being aggressive towards it before.”

The dog, which is usually chained up in a pen outside the owner’s flat in the Sheepridge area of Huddersfield, was said to have been running loose at the time of the attack.

Neighbour Jamie Hanson, 24, said a kitchen knife had been thrown to Mr Ellam as he was attacked, but he did not use it.

Mr Hanson said: “The guy just ended up passing out. He was unconscious, the poor man. When the police came an officer used a fire extinguisher from the car to get the dog off.”

Keeley Berry, who is believed to be related to the victim, wrote on Facebook: “It was a tragic incident that should never have happened and correct measures were not taken to ensure this situation wouldn’t arise.

“We hope that in the coming days, a true representation of what happened yesterday will come to light and end all speculation.

 “At this point, there is nothing to gain from finger pointing or blaming of dangerous dogs or their owners – a man has died in one of the most horrific ways possible, and we should focus on making sure this never happens again rather than playing the blame game.”

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 t