However, he continued working, and was even promoted to senior scientist at Pathlab, where he had responsibility for overseeing the molecular work in the microbiology department.
While Mr Laverty was working at the labs, his responsibilities included processing and interpreting specimens, testing pathogenic micro-organisms and interpreting stained slides.
At a hearing in October, the HPDT was told that there had been no concerns about Mr Laverty's work during the time he practised without a certificate. He was described by one witness as "very competent".
In a decision released today, the Health Practitioners Disciplinary Tribunal (HPDT) said there was "ample evidence that the respondent knew that he did not hold a practising certificate".
"In our view, for any professional person knowingly to practise without a practising certificate is, in and of itself, serious," it said.
"For such a person knowingly to go on living and working in this country when conscious that he or she does not have the necessary immigration status, and take active steps to deceive third parties including his employers, the Revenue and his professional body as to his immigration status and the currency of his practising certificate, is very serious indeed."
The tribunal said it had not found any cases that were similar to this one in its history.
It said the only sensible option was to censure Mr Laverty and order his deregistration. He was also ordered to pay costs of $9735.