"While in the country he also visited Melbourne … where he sprayed some of his famous rat stencils and a 'Little Diver' image around the city, including the famous AC/DC lane. [NB: This image has since been destroyed, despite council efforts to protect it.] "This also represents the last time Massive Attack played in the city, at the Vodafone Arena on March 11 that year, before playing at the Sydney Entertainment Centre on March 14, Brisbane on March 16 and Canberra on the 18th, as part of their Australian tour." [NB: Massive Attack have in fact toured since, including in March 2010, a month before another Banksy stencil in Melbourne was accidentally destroyed by council workers.] It's not the first time the world has woken to the news that Banksy has been unmasked. In 2008, the UK's Mail on Sunday splashed with an expose of Robin Gunningham, "the nice middle-class boy who became the graffiti guerilla". As recently as March of this year, the Mail was trumpeting "we were right", citing scientists who had used "geographic profiling" to "prove" Gunningham was "the only serious suspect".

Which of course hasn't stopped them now asking of Del Naja "is THIS the real face of Banksy?" in an article that appears to borrow heavily from the Bristol Post's initial report on Williams' work. Speaking to Fairfax on Friday, Williams said he was motivated in part to probe the connection more deeply after reading about the geographic profiling that supposedly proved Gunningham was Banksy. Banksy artworks such as this one appeared in Melbourne and Sydney around the time Massive Attack last toured Australia. "I had done some initial research on it and came up with some info, but I guess seeing the criminology mapping study made me want to do more," he said. "I was a little annoyed at some kind of criminal methodology being used to map out Banksy's movements like he was some sort of criminal. That's when I thought good old pen-behind-the-ear journalism shouldn't take second place to that kind of stuff."

Using media reports and social media posts, Williams was able to identify a dozen or so instances of Banksy artwork appearing for the first time soon after Massive Attack played, everywhere from Bristol, hometown of both the band and Banksy, to San Francisco and Glasgow. He also found locations – including Hong Kong, Mali and Naples – where the band had not played but Banksy's work had appeared around the same time as Del Naja had been present in his other guise as a visual artist. This Banksy artwork was first noted in Palestine in August 2014. The previous month, the band had played in Lebanon, at a concert in support of Palestinian refugees. Williams had in fact first floated the idea that Banksy might be Robert del Naja in a blog post in January.

"I have some contacts in Italy and someone I know had made the suggestion that the connection between Banksy and Robert Del Naja had more to it than met the eye," he told Fairfax. The link between the two is well-established – Del Naja was a member of the Bristol sound system the Wild Bunch, out of which emerged not just Massive Attack but also Nellee Hooper, who founded Soul II Soul and produced the early albums of Bjork, and Tricky – and a street artist, using the tag 3D, between 1983 and 86. "I got arrested twice," Del Naja told the UK's Telegraph in 2008. "That was enough." In the same article, Del Naja described Banksy as "a close friend". Elsewhere, Banksy has paid tribute to the influence of Del Naja on his own work. "When I was about 10 years old a kid called 3D was painting the streets hard," he told the street mag Swindle in 2006. "I think he'd been to New York and was the first to bring spray painting back to Bristol. Graffiti was the thing we all loved at school – we did it on the bus on the way home."

The true identity of Banksy (allegedly seen here in a scene from the 2010 documentary Exit Through the Gift Shop) is one of the great mysteries of popular culture. But now the internet has raced to embrace the suggestion that the two are in fact one, Craig Williams is quietly furious. "I'm pretty annoyed at how this has come out as me basically saying that it's 3D," he said. "I wanted to move away from that." Since that first hurried post in January, Williams has been beavering away on his theory, diligently researching correlations and probing his own hypothesis. And the conclusion he has reached is that while there's a strong link between Massive Attack and Banksy, the street art is more likely the product of a collective than of any one individual – including Del Naja.

"I wanted to focus more on the idea that it's a group of artists who share common themes, mirroring the idea suggested in Shakespeare scholarship circles – that such a large body of work was done by many hands rather than one," he explains. Williams says he has spoken about his theory to someone close to Del Naja,"who just laughed it off". He has not spoken to Del Naja himself, though. "I imagine he'd tell me nicely where to go." Which, come to think of it, is probably just what Banksy would say too. Follow Karl Quinn on facebook at karlquinnjournalist or on twitter @karlkwin