As a 22-year-old trainee policeman Kenneth Steele, the first Chief Constable of Avon and Somerset, had no idea what was to confront him when he heard news of a fire in a tenement on his beat in Clerkenwell, London, in 1936.

When he arrived the fire had taken hold and one elderly woman was still trapped in her room. Steele decided to go in, find her and bring her out. He fought his way into the building, climbing the stairs to her floor in dense smoke.

Steele had to break down the door of her room to reach her. But when he got in he found that he could not see the woman because the smoke was so thick and he could advance only by crawling on his hands and knees. Steele found the woman and then dragged her from the building.

However, his efforts were in vain because she did not survive. The policeman, who was still a probationer, himself suffered from injuries to his head and face and spent time in hospital.

The young constable was awarded the King’s Police Medal for his bravery and received it at the only investiture held by Edward VIII before he abdicated.

By the time Steele retired after 45 years’ service he was the only serving officer to hold the KPM and the longest-serving chief constable, having been in charge of a force for 24 years, bridging the gap between the small county and town forces that had existed for decades and the modern network of 43 forces across England and Wales.

Steele was also one of the last, if not the last, surviving graduate of the controversial Police College set up by Lord Trenchard in the 1930s to create a cadre of elite leaders.

Steele concluded his career as dramatically as he started by overseeing his force’s investigations into allegations that Jeremy Thorpe, then Liberal leader, had taken part in a plot to kill a man who claimed to have had a homosexual relationship with the politician. Thorpe and three others were acquitted later.

Kenneth Walter Lawrence Steele was educated at Wellington School, Somerset, and joined the Metropolitan Police in 1933. As a tyro he was posted to the King’s Cross area, where gangs armed with cut-throat razors ran the streets and targeted police. Steele was injured several times, although he and his colleagues patrolled in twos at night for their own safety.

In 1936 Steele was chosen to go to the new Police College at Hendon, set up by Lord Trenchard, a controversial, reforming commissioner. The college was intended to produce a new elite from among young constables and well-educated trainees from public schools and university.

Steele said later that he jumped at the chance to go because he recognised that the college would give him the chance to reach the top. The college wasabhorred, however, by many who saw it as a means to create a snobbish elite based on military ideas of an officer class.

There was public ridicule when it was discovered that trainees were required to have dinner jackets, four dress shirts and patent leather evening shoes among their kit. Steele was among 197 young officers who passed through the doors of the college in the five years of its existence, all elevated to the rank of junior station inspectors after graduation. Despite the criticisms, many of the graduates, like Steele, had highly successful careers in the police.

During the war Steele left the police to become a junior officer in the infantry, serving with The Somerset Light Infantry and The Royal Northumberland Fusiliers.

In 1948, still a member of the Metropolitan Police, he was seconded to the training school at Ryton-on-Dunsmore as staff officer to the commandant, joining a team investigating improvements in higher police training. Steele was involved in the hunt for a new national police college and the decision to take over Bramshill in Hampshire, which is still a national centre.

By 1953 he had become a superintendent and was appointed Assistant Chief Constable of Buckinghamshire. Two years later he was made Chief Constable of Somerset welding together what he saw as a fragmented force of 1,260 officers split between five semi-autonomous divisions. In 1967 the force became the Somerset and Bath Police when the 162-strong Bath city force was absorbed.

Seven years later Steele became the first Chief Constable of Avon and Somerset, with a complement of 2,800 officers created from three forces and welded together despite widespread opposition in the ranks. In his last couple of years in charge he had overall responsibility for the high-profile Thorpe investigation. When Thorpe and three other men were charged at Minehead police station in August 1978 Steele was present.

He was appointed OBE in 1967 and advanced to CBE a year after he retired. He became a member of the council of the Royal Bath and West of England Show and was active locally in the village of West Monkton where he lived.

His first marriage, to Ursula, was dissolved. He is survived by his second wife, Irene. There were no children of either marriage.

Kenneth Steele, CBE, KPM, Chief Constable of Avon and Somerset 1974-79, was born on July 28, 1914. He died on April 14, 2008, aged 93