The 32-year-old has become a cult hero at Carrow Road since arriving from Shrewsbury four years ago. However, the impending arrival of Holland international Ricky van Wolfswinkel has led to reports the club captain could leave, with Melbourne a potential destination.
The A-League side have made an official approach for Holt and, despite reports the offer was rejected, Munn insists a deal could still be struck.
"We made an approach and we always knew that it would be made public, and that with him being contracted for two more years it might be complicated," Munn told SBS.
"But we haven't closed the door on it as yet and will be pursuing it.
"He's a proven finisher and showed that by scoring against Manchester City on the last day of the Premier League season."