Roosevelt Avenue near 91st Street is littered daily with migrant vendors hawking goods they ripped off from shopkeepers just steps away, while prostitutes proposition passersby at all hours — and frustrated merchants and residents say they're helpless to do anything about it.

"It's relentless," said Milton Reyes, who manages Mi Farmacia pharmacy on the avenue. "You should see it on Saturdays. It's so heavy, you can't even step onto the sidewalk. There are a lot of doctors' offices right around here and my customers don't even want to get dropped off.

"I'm not faulting the police," Reyes added. "They will come by and they will pick up a few of them. But as soon as the police car pulls away, they start moving back. Twenty minutes later, they're all set up again like nothing happened."

Migrant peddlers lay out stolen merchandise for resale at a steep discount, with items as benign as mouthwash, diapers and baby formula spread out on blankets or beach towels right on the sidewalk.

The ill-gotten goods are stored in suitcases packed into vans parked across the street, hauled out for display starting in the morning — with one crooked vendor even wheeling up the items inside a stolen Target shopping cart during one business day this week.

They scattered when a reporter and photographer from The Post showed up, mistaking the news crew for police officers — but were back in business as soon as they passed.

Sex workers openly cruise the street, as older madams sit nearby and point out potential johns as they pass by.

One law enforcement source blamed soft-on-crime laws that severely limit what cops can do and cut low-level, non-violent offenders loose once they get to court.