The man, believed to be James Rehill, in his mid 50s, fell to the ground while he was taking the dog for a walk, The Daily Mail reported Monday. He was later pronounced dead.

The animal started licking and pawing Rehill but soon became agitated and started biting and mauling him, said witnesses.

Aziz Rahman, 32, a senior analyst with HSBC, saw the attack outside his house and said the dog threw Rehill around like a "rag doll."

"It was horrendous. His face was unrecognizable. The dog chewed off his ears, bit off his nose and also some of his fingers," said Rahman.

The dog was chased off by a policeman with a fire extinguisher and later destroyed by police marksmen.

Rehill was pronounced dead at the Royal London Hospital in Whitechapel Sunday evening.