The Immigration Department paid more than $22.5 million over a decade to firms owned by a prominent Melbourne migration lawyer, who fled the country owing millions to the Australian Taxation Office.

Despite pocketing multiple lucrative contracts to help asylum seekers apply for Australian protection, Florin Burhala​'s company BMA Lawyers is now in liquidation and owes creditors almost $1 million.

He also owes the ATO about $4 million, and questions have been raised about the quality of advice provided by his firm to asylum seekers needing protection.

Mr Burhala left Australia for Romania, taking millions of dollars, his family, and his pet dog with him, as the ATO was closing in on him in October 2015.

When he fled, the Romanian-born lawyer told authorities he was going to Romania for 21 days on business. It was only later authorities concluded he had left the country to avoid his tax debts.

But the ATO is all but powerless to get its money back, with deputy commissioner of taxation Aris Zafiriou​ telling the Federal Circuit Court that authorities didn't even have Mr Burhala's forwarding address.

Mr Burhala also left in the lurch about 100 asylum seekers, who had only had their first visa application lodged by BMA.

A Fairfax investigation can reveal that the Immigration Department continued to give money to Mr Burhala's companies through lucrative contracts, even after he became involved in a long-running tax dispute with the ATO, and one of his companies collapsed.

BMA Lawyers, which has been in liquidation since January last year, was contracted by the Commonwealth to provide migration advice to asylum seekers under the Immigration Advice and Assistance Scheme between 2011 and 2016.

A previous firm owned by Mr Burhala, Florin Burhala and Associates, held contracts with the department between 2006 and 2011.

Florin Burhala and Associates went into liquidation in 2013, according to ASIC documents.

BMA's contract was amended just months before he left, with the department agreeing to raise his contract to a $11.67 million value – increasing it by more than $91,000 in July 2015.

An immigration spokeswoman said all IAAAS contracts with Mr Burhala's firms had complied with Commonwealth procurement guidelines, and no payments were made after his contract expired.

But Mr Burhala had been involved in a long-running dispute with the ATO since 2009, according to an account provided by his lawyer to the Federal Circuit Court last year. Mr Burhala maintained that he didn't owe a debt to the ATO, although Judge Philip Burchardt rejected this.

BMA was put into external administration on January 5, 2016, and in October the Federal Circuit Court issued bankruptcy orders against Mr Burhala.

The ATO alleges that through another company of which Mr Burhala was director and sole shareholder, Aspen Alpine, millions of dollars were funnelled to Romania in October 2015, with further "major" transfers sent in November 2015.

Mr Burhala left behind a $3.7 million tax debt, which continues to attract interest and was valued at $3.9 million in July last year.

Immigration Department secretary Mike Pezullo told senators late last year that the 100 asylum seekers left in the lurch by BMA would have their paperwork handled by another firm, UAM Lawyers. There is no record of that firm existing, but AUM Lawyers is directed by Mr Burhala's former colleague, Attila Mete.

Mr Mete is a former partner at BMA Lawyers, and Florin Burhala and Associates, and also represented Mr Burhala in the Federal Circuit Court dispute over his multi-million dollar tax debt.

Greens Senator Nick McKim, who requested more information from the department about the case, said the department should review cases handled by BMA.

"I've had concerns raised with me by people who work in the refugee legal sector that BMA did not always provide an acceptable level of support and advice to highly vulnerable people and ... that the quality of advice in some cases was so poor that there is a risk that people had their cases prejudiced by the low standard of support and advice and basically received inadequate representation."

A spokeswoman for the ATO said the organisation did not comment on individual cases.

Fairfax Media contacted the administrator and Mr Mete for comment, but they did not respond. Fairfax was unable to contact Mr Burhala.