Charles Turner, a music composer who was recruited as a spy, took the photos at the Wagner Festival in Bayreuth, Germany, in 1939, where he joined Hitler's entourage, his son David Turner said. He was one of the last Englishman to speak to the dictator before Nazi forces invaded Poland on Sept. 1, 1939,
The composer first attended the festival in 1934, and each year Hitler was also there. In 1938 - when war seemed imminent - Turner was recruited as a spy, his son said.
"The miraculous happened. My father was invited to join Hitler's entourage for the day, Wednesday, July 26. He was given carte blanche permission to photograph the fuehrer," David Turner said.
The composer met with Hitler and senior Nazi officials - including propaganda minister Joseph Goebbels and Hitler's deputy, Rudolf Hess, Turner's son said. Afterward he sent a detailed report back to London that remains classified.
The photos include images of the leader getting out of his car, in a relaxed conversation with a fellow Nazi and collecting flowers from children at the festival.
Charles Turner died in 1977 and the photos were kept as family mementos after his death. His son, a teacher, decided to make the photos public now after he started researching his family's roots.
He has sold the syndication rights to the photos to a small British photo agency.