"He's a big fan of the band and just wants to be involved."
Listen to Fletch, Megan and Vaughan's interview with Chris Mac:
Mac went on to confirm that they been working on new music together - and he could feature on the group's upcoming album.
"At this very second we are working with completely fresh stuff with him. There are talks to get him involved on a couple of tracks from the album."
Williams, an award winning producer and singer, first met Six60 in 2013 at the South by Southwest festival in Austin Texas after Kiwi fans on Twitter brought the band to his attention.
At the time, Walters described him as a "massive inspiration".
Six60 were signed to Sony's European label Columbia Four Music label in 2013, while Williams is associated with Columbia, a subsidiary of Sony US.
The band's first album debuted at number one in New Zealand, with the first two singles Rise Up 2.0 and Don't Forget Your Roots reaching No. 1 and No. 2 respectively on the RIANZ singles chart.
- nzherald.co.nz