The problem is that most of the people in a position to know first hand, or be named were dead by 1948. Of those who were not dead, highest ranking Nazi most likely to have had some sexual contact with Hitler is Rudolph Hess.
The same claims of homosexuality are made against J. Edgar Hoover. Claims made it should be noted after he was dead. The morals at that time were so strictly exclusive of sodomy that the slightest hint would have destroyed him. Hoover was so powerful and thus made so many enemies that if in fact he was a cross dresser and/or homosexual those very same enemies would have seized upon those "facts" and destroyed him. Even Presidents feared that man's data files.