A quick chat to Detective Sergeant Paul Slater reassured him the medal was "in good nick".
"I was over the moon. The crazy thing is even though I was really hopeful, I was not expecting to get it back."
There were so many variables, he worried the person who took the medal would panic and bin the medal under pressure, Nyika said.
His girlfriend had stayed in touch with the police during the attempt to find the medal, as it was a topic that held a lot of emotional weight for him, he said.
"It's more a measure of my persistence and my resilience to overcome the trials I have had over the last four years ...
"It was a huge achievement for me."
Nyika said he was grateful for the way the people in the community had rallied around him.
His mother played hockey with a policewoman who he credits as encouraging him to come forward.
"She was the first one to say, 'hey, better to cover your bases, come in and have a talk'.
"I was a little bit reluctant because I was a little bit embarrassed, but she kind of talked me around."
She had told him that no matter where he parked his car nobody had the right to go through his stuff, he said.
"The police have done a wicked job.
"I'm just looking forward to finding out more details - so is everyone else, I think."
Slater confirmed today the boxer's medal was with police.
"Firstly everyone in the CCTV footage was identified and most importantly we got the medal back!", Waikato police said on Facebook.
"That is so awesome! Well done to Paul and your team. I am sure David Nyika will be stoked."
Slater said the investigation was ongoing and for that reason police were not in a position to discuss details of how the medal was recovered.
"The medal has not yet been returned to the victim however police is looking to facilitate this as soon as possible."
Police had previously released CCTV images from an Auckland retail premises of people they believed could help locate the medal.
During the public appeal, Nyika had asked for those responsible for stealing the medal from his car in Hamilton to return it – "no questions asked".
He told the Herald he had the medal in his car because he was often showing it to children on school visits and it was shortly before one of those appearances that he realised it was missing.