Detectives are investigating whether the death of a pensioner, who was savagely attacked by a gang outside his home almost two years ago, was murder.

Keith Alder was beaten with baseball bats and kicked unconscious in the brutal, unprovoked attack in October 2011, which led him to have both legs amputated above the knee.

Earlier this year a Keighley man, Ladislav Balaz (right), of Samuel Street, was jailed for 16 years for his part in the assault.

Now, following the death after a stroke of Mr Alder, 68, at Bradford Royal Infirmary on August 7, police are probing whether there is a connection with the attack. A post-mortem examination has been carried out by a Home Office pathologist.

A West Yorkshire Police spokesman said: “A police investigation is under way to establish whether there is a link between the assault in October 2011 and the subsequent death.”

Mr Alder, a roofer, had only just retired when he was left for dead by the gang outside his then home in Great Horton, Bradford.

The father-of-three had been looking forward to spending his retirement pursuing his love of fishing, but instead endured a string of medical problems as a result of the attack.

He spent almost eight months in hospital and suffered head injuries and kidney damage, which led to pneumonia.

Emergency surgery was needed to remove most of his bowel after scans revealed it had rotted, and he was then put into an induced coma for a week. He contracted an MRSA infection and gangrene cost him both legs above the knee. He also lost six-and-a-half stone.

But Mr Alder had been on holiday and was driving again and his family believed he was on the mend.

In February Balaz was jailed after being convicted by a jury of grievous bodily harm with intent.

His uncle, Bartolomej Makula, was jailed for 15 years in April last year after pleading guilty to causing Mr Alder grievous bodily harm with intent and possession of a baseball bat.