"We continue to appeal for people to come forward with information. Although the investigation has been going for a month we are still discovering people who potentially have crucial information who have not come forward."
Mr Whitehead said the investigation team is working to establish everyone who went to Mykonos on the night of Sunday, June 17, and everyone who was out walking or driving about the central area
of Paeroa between 10pm on the Sunday and 6am on Monday, June 18.
"The police now believe that Mr Voudouris was shot sometime between 1.30am and 4.30am on the morning Monday of 18 June but the offender(s) activity either side of this time frame may have attracted someone's attention," Mr Whitehead said.
"Given we have revealed that Mr Voudouris was the victim of a shooting we would now like to hear from anyone who knows of firearms being stolen, anyone having firearms who should not have and any activity involving firearms that was suspicious or out of the ordinary.
Police have set up Facebook page and a website to assist the investigation.
Mr Whitehead said anyone with information should contact Paeroa Police on 07 862 8744 or Crime stoppers on 0800 555 111.