In 1997, he was convicted of aggravated robbery and theft of property at a pharmacy in the hospital complex in Arkansas. He also admitted to holding up a pharmacy for narcotics a few weeks earlier. He pleaded guilty to the charges and was imprisoned for 10 years in the US.
Middleton was released from prison in 2007, and returned to New Zealand in 2012 after working as a chef.
He applied for a practising certificate with the Nursing Council in 2013, but in his application said he had not practised overseas, nor had any criminal history.
His CV said for the years between 1996 and 2013 - much of which he was imprisoned - he ran a home-based audio business and cared for his autistic son.
The licence was granted, and only suspended after the council became aware of his prior convictions.
In 2015 Middleton was convicted by New Zealand police of importing a prescription medication called Isoniazid. He told Customs staff he was a research chemist who needed the drug for an experiment. He later admitted in was for personal use.
In a Health Practitioners Disciplinary Tribunal decision released today, the Professional Conduct Committee said Middlebrook's conviction was "an extremely serious matter".
It said his continued offending and false declarations showed "a continuing pattern of dishonesty".
"Honesty, trust and accountability are fundamental obligations in the nursing profession... We are satisfied that this case sits with other comparable conviction and dishonesty cases that warrant cancellation."
Middlebrook was ordered to pay costs of close to $7300.
