A former secondary school teacher of a Kiwi rugby star turned Irish international has revealed how giving a ride home from central Auckland spared his pupil, who was being spoken to by police.

Michael Wagener has recounted on social media how 15 years ago he saw a young Bundee Aki "being hassled by police" in Aotea Square.

Wagener said Aki spotted him and called out, telling the officer that the pedestrian was his teacher.

"The police officer said , 'Are you his teacher?' I confirmed that I was," posted Wagener.

The teacher was told that Aki was being disorderly and that he was going to be taken in for processing.

"As far as I know, he's managed to keep himself out of trouble ever since.

"Hopefully when he's out celebrating his try against the All Blacks tonight, Bundee Aki doesn't get any grief from the police, and doesn't need anyone to take him home this time," he posted.

Wagener went on to explain he was being "more of a clown" than aggressive.

The rugby star's old teacher has been praised by others on Twitter commending him for his actions.

"What an awesome teacher," wrote one.

"Good teacher story!" posted another.

Aki, who was born and raised in Auckland but now represents Ireland after qualifying through residency, was one of three Irish internationals who played for their adopted homeland last night.

Jamison Gibson-Park, Bundee Aki, and James Lowe have played rugby professionally, and started their careers, in New Zealand.

Aki went on to score a try against the All Blacks in the Eden Park clash, with the visitors losing 19-42.