State officials are investigating how an apparently drunken man fell to his death through an open Columbus Circle manhole and managed to go undiscovered for two weeks.

The manhole cover at West 58th Street and Eighth Avenue was open again Wednesday, as Verizon workers returned to the scene to try to blow out the stench from the badly decomposed corpse, discovered Tuesday partially eaten by rats, authorities said.

A large hose pumped air into the opening, but the smell of decay continued to hang over the neighborhood.

Inside the hole there’s a 20-foot drop, one worker said, but a maze of wires from various utility and telecommunications companies snakes across the opening closer to the top.

Sources told The Post the body was found somewhere among those wires.

The state Public Service Commission on Wednesday said it will launch an investigation “to determine whether there were any regulatory violations.”

“If there were violations, the company could face financial penalties,” PSC spokesman James Denn said.

Surveillance video from a nearby building shows the ­unidentified man stumbling through barriers and into the open hole at around 2:30 a.m. on Sept. 30, police sources said.

Hours later, Verizon workers are seen returning to place the metal cover — which can weigh up to 300 pounds — back on the hole, not realizing the man was inside.

Police said the man might have been homeless, and possibly between 30 and 40 years old. He wore shorts and a T-shirt.

It is unknown if he was killed in the initial fall or if he died a horrific, slow death after tumbling into the hole.

The city medical examiner is due to release autopsy results that could determine the cause of the man’s death — and possibly his identity.

A Verizon worker said Wednesday that the utility would remain at the scene around the clock until the city’s Department of Environmental Protection shows up to make sure the cleanup is complete.

“Until the higher-ups give the go-ahead, we can’t shut it down,” the worker said. “We have to be here, and that’s all they’ve told us right now. Really, we are waiting on the [DEP].”

Verizon did not respond to ­repeated calls and e-mails seeking comment.

The DEP also did not respond to requests for comment.

But the grisly episode remained the talk of the neighborhood on Wednesday.

“It’s alarming, to say the least,” said Jersey City visitor Tiffany Adams. “I’ve never heard of anything like this before.”

“Poor dude,” added Brooklynite Jeff Sykes, who works nearby. “It’s so sad. Don’t fall in a manhole. People aren’t aware of their surroundings with their headphones and their rectangular devices they’re walking around with.”

Some even came up with conspiracy theories about the man’s horrifice demise.

“Maybe he saw something or somebody doing something and that person did away with him,” said construction worker Javier Cruz. “I just don’t understand, with so many cameras, why they don’t know more.”

Additional reporting by Bernadette Hogan and Alex Taylor