The 77-year-old was last month named by the royal commission investigating allegations of abuse at a Hobart school in the late 1960s.
It was believed he had moved to South Africa and later died. But he was tracked down by the Australian newspaper to Manawatu this week.
When visited by NZME. News Service yesterday, Mr Thomas was home but did not come to the door. But his partner said Mr Thomas had been living in New Zealand since about 1973 or 1974 and teaching "all over New Zealand". He said Mr Thomas had been asked to give evidence to the commission and that he strenuously denied the claims.
"Of course he says it's not true," Mr Thomas' partner of about six years said.
Mr Thomas was "going under a lot of pressure" and was not keen to comment.
Teachers Council spokeswoman MaryRose Painter said Mr Thomas became a registered teacher in New Zealand when the requirement came into effect in 1990.
He had passed a criminal record check and was endorsed by his principal as part of the registration process.
Since then, Mr Thomas had not been subject to any complaints or disciplinary proceedings, Ms Painter said.
The council's screening process was now more robust and included a full police vet in NZ and any country the teacher had previously worked in which extended beyond a check for convictions, she said.
"If he was applying now, we would know that he taught in Australia and we would have sought a report or police vet from Australian police."
Mr Thomas told the council in 2002 he no longer taught and his registration had since lapsed, Ms Painter said.
Mr Thomas' Old Friends profile records he was employed at Whangarei Boys High from 1981 to 1990.
He had taken a teaching job in Western Samoa.