Mr Muir said if the band had been asked to play at Glastonbury it would have accepted the invitation.
"I can't tell you any more than that."
Singer Martin Phillipps said The Chills had never played Glastonbury.
Although he would not confirm if The Chills had been invited, the band would "definitely" be performing internationally this year, he said.
Glastonbury Festival starts on June 25 and finishes on June 29.
Festival-goers paid $405 to attend the festival last year, which was headlined by The Rolling Stones and the Arctic Monkeys.
Six60 bassist Chris Mac said when his band was invited to perform at the festival last year, it had about three months' notice and was sworn to secrecy until a week before their performance.
"You don't want to announce until the festival announces."
New Zealand Music Commission international manager Gary Fortune said Glastonbury organisers want performers to keep quiet so they could control the announcements to the media.
"If someone at Glastonbury gets invited to play, they'll be told so they can accept the invitation and get themselves sorted out but will be told to stay schtum until Glastonbury goes out and says here is the next wave of bands playing."
A Glastonbury invitation was a great chance to be exposed to a large international audience, he said.
