UK Telegraph reports:
Appearing on the Late Show with David Letterman he was asked whether the two characters had a "different level of relationship" beyond solving crimes, and replied: "You mean that they were homos? That is what you're saying?"
The actor also suggested that Dr Watson's fiancée could be a cover for the relationship between the two male characters, and introduced a clip of Holmes wrestling by inviting the audience to decide if he was a "butch homosexual".
"Robert can't stop talking about the world's most famous 'bromance' and it's making studio publicists very nervous," one Hollywood insider said. They added that executives did not want the film to become "Brokeback Mountain 2", referring to the Oscar-winning movie about two gay cowboys.
Downey Jr has dropped a series of other hints about the subtext of the Guy Ritchie-directed film, previously describing the lead characters as "two men who happen to be room-mates, wrestle a lot and share a bed".