Diddy never seemed happier than on the streets of his hometown of New York Monday night — a scene that offered no hint the music mogul would soon end up in federal custody facing a criminal indictment.

TMZ obtained new video of Diddy interacting with several excited fans on a darkened street in Midtown Manhattan approximately 30 minutes before federal agents arrested him at the Park Hyatt Hotel nearby.

Check out the footage … Diddy was having a very friendly chat with four dudes — and everyone was wearing bright smiles on their faces. Diddy was so energized he gave a handshake to one of the guys who bowed and started laughing.

We have also obtained footage of Diddy and his crew hanging right outside the Park Hyatt Hotel shortly before he was arrested.

Hours earlier … Diddy was photographed strutting around NYC with his son Christian ‘King’ Combs. The two stopped to say hello to pedestrians and take selfies with them.

After his little street gatherings, Diddy was arrested late Monday by the feds at the Park Hyatt and hauled away to the federal building in lower Manhattan.

Diddy is now facing a grand jury indictment currently under seal. As you know, Diddy has been under federal investigation for sex and narcotics trafficking as well as other serious offenses.