"All you need is a name," Auckland-based private investigator Julia Hartley Moore told the Herald.
But how Lotto might be able to find out the name of the winner was up in the air, she said.
Private investigator Julia Hartley Moore. Photo / Supplied
However, Lotto has confirmed specific information could be uncovered, including what day the ticket was bought, the exact time and whether a credit card or Eftpos was used.
Hartley Moore hypothesised Lotto would then be able to uncover the winner's bank account to then get a name, something private investigators couldn't do.
"Your bank account details are private, like your phone records. A private investigator doesn't have any authority to look into those - only the police," she said.
"That's breaching all of the privacy laws but maybe Lotto has other avenues that we don't know about, I don't know."
The only way around being tracked by your bank account was by using cash.
In 2013, video footage from Pak'nSave Riccarton in Christchurch was used to track down a man who was unaware he had won $22 million.