If the conspiracy buffs are right, you’ll want to be on the lookout for witty graffiti popping up around New York City this weekend.

That’s because British trip-hop group Massive Attack, fronted by vocalist Robert “3D” Del Naja, is playing Radio City for a three-night run starting Thursday.

Some believe that Banksy, the elusive, anonymous creator of politically cheeky graffiti and Del Naja — who sings about having “a soul without a mind” and “a body without a heart” — are the same person.

The theory was popularized in 2016 when Craig Williams, then a student at Glasgow Caledonian University and now a freelance journalist in the Scottish city, aimed to take on a major project for his class in digital media.

“I wanted to figure out the number-one pop culture question: ‘Who is Banksy?’ ” Williams told The Post.

On a hunch, “I tried matching Banksy to a musician and it led me to Robert. I got there by looking at when Banksy’s pieces were reported in the news and seeing what bands were playing in the particular cities at that time. In places that included Los Angeles, Melbourne, Toronto and New York, Banksy and Massive Attack matched. They played and his art was discovered [soon before or after the shows]. It seems to be more than just coincidence when that happens 10 to 12 times.”

For instance, on Sept. 28, 2013, Massive Attack performed a live one-off event at Manhattan’s Park Avenue Armory. Del Naja and company provided the soundtrack for a movie called “Massive Attack V Adam Curtis.”

Then, for the month of October, Banksy plastered the city with images that included a peeing dog on a Chelsea wall and a man with a wilting bouquet splashed across the security gate of Larry Flynt’s Hustler Club.

If the timing lent credence to Williams’ belief, that outcome may have been doubly appealing to Banksy. “He wants people to have as many theories [about his identity] as possible,” said Seth Carmichael, a New York-based dealer of secondary-market street art who once specialized in work by the spray-painting provocateur. “That keeps the whole myth alive.”

Anonymity and mystery have benefited Banksy — his 2009 piece, “Devolved Parliament,” comes up for auction at Sotheby’s on Oct. 3, with an estimate of around $1.8 to $2.4 million — but Williams believes that certain facts unmask his true identity.

Banksy and Del Naja both spent formative years during the 1990s in Britain’s southwest city of Bristol. According to Carmichael, they came up as parallel graffiti stars in the city. Banksy was part of the prolific DryBreadZ Crew and Del Naja has been described as Bristol’s “spiritual leader of the graffiti scene.”

If he is not actually Del Naja, Banksy is indeed a fan of Massive Attack, and Del Naja has described him as a “mate.” He had a cameo in Banksy’s 2010 art-world sendup “Exit Through the Gift Shop,” while Banksy wrote the intro to Del Naja’s 2012 book “3D & the Art of Massive Attack.”

In Banksy’s Walled Off Hotel on the West Bank — which opened in 2017 and remains a functional place to stay, with nine rooms — the piano bar (adorned with intentionally vandalized Banksy oils) features a fireplace with Massive Attack’s flame logo on the back wall.

Interviewed for the pop culture magazine Swindle by fellow street artist and Swindle founder Shepard Fairey, Banksy talked about Robert “3D” Del Naja in near iconic terms, describing the artist/musician as the person who first exposed him to graffiti. “3D quit painting and formed Massive Attack,” said Banksy, “which may have been good for him but was a big loss for the city.”

There have been other attempts to find out who the real Banksy is.

In 2003, the cagey street artist did his one known interview with a mainstream journalist. A reporter for the Guardian spoke with Banksy on the eve of his first gallery show.

He described Banksy as resembling a cross between rapper Mike “The Streets” Skinner and musician/actor Jimmy Nail. Banksy said he would not be attending his opening and that his parents have no idea of what he does. Halfway through the story, the writer wondered if he was actually interviewing Banksy or an imposter.

In 2008, the Mail on Sunday ran a photo of a man crouched down alongside a car, claimed he was Banksy and maintained that the artist’s real name is Robin Gunningham, who grew up middle class in Bristol and attended a private school there where he played rugby and is said to have excelled at art.

Banksy’s UK-based art dealer denied the claims, but as recently as last year, video footage surfaced that dubiously claimed to capture Gunningham sitting in a van in Hull, England, where three new Banksy works were spotted.

The man who took the video, a local scrap dealer, said: “I can’t believe that there was this millionaire sat in this van spraying paint onto a wall.”

In this era of video surveillance, social media and facial recognition, it’s shockingly impressive that Banksy has been able to hide his identity for this long.

How does he do it?

“He is very good to the people he trusts,” Carmichael told The Post. “The inner circle is very loyal. [Members of the circle] are as tight as it gets. Nobody has ever turned on him.”

Still, there are details that link Banksy and Del Naja.

“Robert was represented by Banksy’s former dealer,” Carmichael said. “Banksy is very music-centered and I’m sure he goes to a lot of [Massive Attack] shows. If he does a graffiti piece, it brings attention to them. They are very close friends and Robert is part of the inner circle.”

Apparently, so is one of Hollywood’s more controversial stars. “[Banksy] lived in the Hollywood Hills for a while,” continued Carmichael. “He and Johnny Depp were incredibly close.”

Celebrity collectors of his work — which, on the primary market, said Carmichael, is sold only to insiders who get demoted to outsiders if they go on to sell those works — are said to include Brad Pitt and Angelina Jolie.

Carmichael told The Post that he does not believe that Banksy and Del Naja are the same person.

When asked if he is personally acquainted with Banksy, the dealer responded, “Know him? I can’t answer that question.”

When Robert Del Naja was on stage for a Bristol homecoming concert in 2016, he did nothing to quell rumors by announcing to the audience, “We are all Banksy!”

Days earlier, Del Naja told the Mail, “Rumors of my secret identity are greatly exaggerated. It would be a good story but sadly not true.”

Unwavering as ever, Williams describes Del Naja’s denial as “an easy get-out.”

Williams had the opportunity to ask Del Naja himself when Massive Attack played Glasgow this past January and he met the vocalist.

Initially, said Williams, “I was hesitant because I was afraid he would punch me in the face. But he was in high spirits and I’m sure alcohol was involved, so I told him that I’m the one who came up with the theory of him being Banksy. He mentioned that his privacy had been compromised because the tabloid media jumped on him.

“Then we joked that it has not harmed ticket sales for the tour.”

Did Williams pop the big question? “I didn’t. Whatever he would have told me — yes or no — it could have been a lie.”

Also, the truth could have been more complicated than a simple yes or no answer.

Patrick Potter, author of 2012’s “Banksy: You are an Acceptable Level of Threat,” made the point that Banksy’s undertakings have become too large for him to be functioning solo. Potter and others believe that Banksy works with a collective that, as the author put it to The Post, may be composed of “20-year-old arts graduates from Bristol.”

They would be handy for his street art, which tends to be spray-painted via stencils, and necessary for more conceptual pieces, such as the mobile waterfall installed in the back of a roving truck during Banksy’s New York stand in 2013.

Considering that Del Naja and Banksy might work in collaboration, Potter wondered, “Could Robert sneak around in the night, throwing up stencils? Maybe [Banksy] sends Robert some files and says, ‘Hey, if you have a minute, go ahead and throw up a piece and let’s see if somebody takes out a giant concrete wall and tries to sell it.’ They would both have a good laugh at that. Maybe they are the Merry Pranksters of the modern era. It’s all about mind games and messing with the culture of art and celebrity.”

As to whether New Yorkers should brace themselves for being messed with this weekend, Carmichael said, “There is always a chance. Banksy loves New York, he loves Massive Attack. It would not be out of the question.”