"They opened a bank account so cadets and staff could secretly collect the money for our flight and allow us to surreptitiously arrive during a 'mock parade' that doubled as a surprise birthday celebration for one of the tutors as well," Mr Stevenson said.
After arriving in Australia, the couple were driven from the airport to the Brisbane Police Academy in a marked police car, and on arrival had to be hidden before they were handed over to a protocol officer to wait for the sham parade to begin.
"We met several high-ranking officers as well as the cadet who organised the trip. At the parade the cadets began singing Happy Birthday to their tutor so the commissioner could walk myself and Rosemary unobserved between two groups of cadets to a point just behind the flag-bearers.
"At the end of the song Ben had to march from the ranks to the rostrum, where he was to read his declaration of allegiance to the state and Queen. So he had his back to us until he turned to face the assembly," Mr Stevenson said.
"His eyes swept across the crowd once, twice, and on the third sweep he saw us. His mouth dropped open and tears came to his eyes. Several others had tears in their eyes as well."
Mr Stevenson said the couple, who have five adult children, were proud of their son's achievement and grateful to his fellow recruits and tutors for the opportunity to be at the graduation.
He said the bona fide ceremony was memorable and included displays of dog handlers, pipe bands, motorcycle police and, of course, the swearing in of their son as a Queensland police constable.
Mr Stevenson said his son, who was home-schooled and holds the Boys Brigade Queen's Badge Award, had started his working life as a Wairarapa Times-Age paper boy ahead of several other jobs in Masterton before he left for Australia several years ago.