Mr Whittall attended university at Woollongong, near Sydney, and his Linked In on-line profile gives his current location as Sydney.
His lawyer Stacey Shortall, of Wellington, confirmed today that Mr Whittall "had returned home to Australia".
He moved home permanently earlier this year, she said.
Mr Whittall's on-line profile says he is a consultant at Peter Whittall and Associates. It also states his former role at Pike River Coal.
In December, all charges against Mr Whittall arising from the November 2010 mine explosion that claimed 29 lives, were dropped.
The Ministry of Business, Innovation and Employment cited the lack of witness availability as a key reason for abandoning the prosecution.
Fourteen witnesses were living outside New Zealand - predominantly in Australia - and Crown lawyers had no power to summons witnesses living overseas.
The Council of Trade Unions is considering a judicial review of the decision to drop the charges against Mr Whittall.
Every mine manager at Pike River was a foreigner.
Doug White is a Scot who now lives in Australia, Kobus Low a South African, Nigel Slonker and Steve Ellis Britons, and Mick Lerch an Australian.
A few weeks after the disaster, former Pike River Coal chairman John Dow said of Mr Whittall: "If he hadn't been born in Wollongong he probably should have been born in Greymouth because the people in Greymouth see him as a Coaster and if you could see the outpouring of love, support and affection that he has received during the past few days, it's boosted his sense of belonging to this community."
- By Laura Mills of the Greymouth Star
