Mark Sowter (24) suffered serious head injuries in the suspected assault near Blind Lane, Wirksworth, about 8pm, on Saturday, June 5, and was taken to Nottingham Queen's Medical Centre for treatment.

A Derbyshire Constabulary spokesman said: "We're investigating a suspected serious assault where the injured person was originally left in a critical condition with head injuries."

Senior investigating officer Det Supt Dean Wheeldon is appealing for witnesses or anyone with any information about the incident to call Derbyshire Constabulary's Matlock police station where an investigation incident room has been set up.

A police spokesman revealed the injured man was still recovering in hospital and has been too poorly to discuss exactly what happened to him.

Police have arrested and interviewed an 18-year-old male under suspicion of committing assault and he has been released on police bail pending further enquiries.

Officers are still appealing for anyone with information about the incident to come forward.

Mr Sowter and friend Jason Carmen received praise for their heroics from Derbyshire fire service after they ran into a burning house, on Gorsey Bank, Wirksworth, last June, to rescue the occupant.

Mr Sowter also re-entered the heavily smoke-logged property to save the man's bull-terrier dog.

The 24 year-old had heard a smoke alarm and spotted smoke coming from an upstairs window of the affected property near his parents' home before he sprang into action.

Anyone with any information about Saturday's incident should call Derbyshire Constabulary on 0345 123 3333 or Crimestoppers in confidence on 0800 555 111.