The last surviving witness of Adolf Hitler's final days in the Berlin bunker who always referred to the Nazi dictator as "the Boss", has died in his home at the age of 96, his book agent has said.

Rochus Misch, who told Reuters in a 2007 interview that there was a strange silence in the bunker as the battle for Berlin raged above in April 1945, had been suffering from the effects of a recent heart attack when he died on Thursday.

"His family was with him when he died," Misch's agent, Michael Stehle, said. He died in the modest house in south Berlin where he had lived since 1938.

In the 2007 interview, Misch who worked as Hitler's bodyguard, phone operator and courier for five years said "Life in the bunker was pretty normal. Hitler was mostly very calm."

He said historians, filmmakers and journalists always got it wrong when they described the mood in the bunker as Soviet forces closed in on Hitler in the final days of the Nazi regime.

"It was much less dramatic than shown by many historians, filmmakers and journalists," said the former soldier.

"The worst thing was the silence ... Everybody was whispering and nobody knew why. That's why it felt like the bunker of death."

Misch remained neutral on Hitler up to his death. "History is history, it was the way it was and nobody should lie about it," he said, refusing to make judgements about the past.

The only soldier allowed carrying a weapon in the bunker, Misch joined the SS in 1937 aged 20 and was wounded in 1939 in Poland.

He recovered and was reassigned to Hitler's chancellery. He was captured after the war and spent nine years in Soviet prisons.

Source: Agencies