Last year, a researcher claimed Del Naja is Banksy which he denied - but listeners say Goldie's gaffe appears to confirm his identity.
Goldie's bombshell occurred around 38 minutes into an interview with spoken word poet Scroobius Pip for his Distraction Pieces podcast which aired on Tuesday.
In it, Goldie is ranting about how the art industry is cashing in on Banksy.
He says: "Give me a bubble letter and put it on a T-shirt and write 'Banksy' on it and we're sorted. We can sell it now. No disrespect to Robert, I think he is a brilliant artist. I think he has flipped the world of art over."
Scroobius Pip says: "Yeah, completely."
Goldie, real name Clifford Joseph Price, MBE, then pauses for a few seconds before changing the topic to jazz music.
But while the huge slip-up seems to have gone unnoticed by him and the interviewer, one listener cottoned on.
The fan said: "They were talking about Banksy and then he referred to him as 'Robert' and I put two and two together. I'm just a random listener but I've heard the rumours - it made my ears prick up."
Banksy rose to fame for his provocative stencil work in the late 1990s and ever since, the mystery surrounding his identity has deepened.
At a similar time, Massive Attack were releasing Mezzanine and Del Naja was being credited as the first graffiti artist in Bristol.
According to an investigation by journalist Craig Williams, six Banksy murals were reported in San Francisco on May 1, 2010 after his Del Naja's band performed a two-night stint in the city that April.
Massive Attack played Toronto a week later before more new Banksy murals were reported there. Later on that tour, Massive Attack headed to Boston's Chinatown a day after a Banksy appeared there.
Similar patterns are reported in 2006 when Massive Attack embarked on a US tour a week before Banksy's Barely Legal exhibition in the city.
In 2008, Bristol street artist - or group - Banksy produced 14 stencils across New Orleans marking the third anniversary of Hurricane Katrina. Del Naja co-wrote the soundtrack to the New Orleans-themed documentary Trouble the Water during the same time frame.
Also in April 2003, Banksy's work appears in Melbourne, the same city Massive Attack had played the month before.
Del Naja also appeared in Banksy's Exit Through The Gift Shop speaking about the pair's friendship from his early days in the city. And Banksy even provides the foreword to Del Naja's book 3D and the Art of Massive Attack, which was released last year.
The global graffiti star has also previously been named as public schoolboy Robin Gunningham.
