Sydney developer Merhis Corp and a clutch of related entities have gone into liquidation owing the Australian Taxation Office at least $6 million and its director Mark Merhi has left Australia.

Helm Advisory managing director Stephen Hathway said he triggered the liquidation of the 23 Merhis companies last week after they defaulted on a settlement agreed three years ago, leaving a separate tax bill of about $16 million for income tax owing, and GST collected on unit sales and never paid.