Did Alfred Hitchcock make a secret cameo appearance in drag?

Debate is raging on movie message boards over whether a plump, jowly woman who briefly features as a train passenger in North by Northwest was actually the acclaimed film director in drag.

Hitchcock was known for making quirky cameo appearances in his movies, but was never previously thought to have played a woman.

The key scene comes around 44 minutes into North by Northwest, which was released in 1959. The woman, who is wearing a turquoise dress and blue and white hat, is one of several passengers who have their tickets checked by an inspector.