Meghan Markle's Nephew Was Naked, Screaming During Hollywood Arrest

Meghan Markle's nephew, Thomas Dooley, quickly lost his towel and was butt-ass naked during his rowdy arrest in Hollywood last week ... which we now have on video.

TMZ obtained footage of the arrest from Thursday, which took place right around the corner from the Hollywood Hotel just north of Santa Monica Blvd. As you can see ... it was a noisy affair, as officers attempted to detain Dooley..

We broke the story ... Thomas was arrested and ultimately booked for felony resisting arrest after police say he was spotted cruising up and down the boulevard covered only by a small towel.

Cops say he was also shouting gibberish to himself, and appeared to be under the influence of some substance. We're told he had to be taken down after evading police.

By the time cops loaded him in the car, Thomas was fully naked and in this video you can hear him screaming loudly several times as officers apprehend him. There was even a chopper on the scene.

Eyewitnesses tell us that at one point, Thomas was becoming so unruly in the car ... he was taken out, strapped to a gurney and a paramedic treated him on the spot. Law enforcement sources confirmed Thomas was taken to a hospital.