About a thousand subcontractors are owed $41 million from construction companies formerly part of the Hawkins Group, liquidators say.

In an unusually complex report, covering ten companies from the group, BDO's Andrew Bethell and Andrew McKay outline a lattice of $400m in related-party lending and $37.5m owed for retention payments or to trade creditors.

The vast majority of unsecured creditors - a listing of which fills more than ten pages of the report into the group of ten - are owed by treasury company Orange H Construction, and two H Construction companies established to respectively manage projects in the north and south islands.

Outside of related-party loans payable, assets of the group and school-building company amount to $2.9m.

"It is too early to estimate what funds, if any, will be available for unsecured creditors," liquidators said in their report.

Liquidators were yet to quantify the amount owed to secured creditors but noted they had been informed by receivers that "substantial amounts" were owed to parent McConnell Group - not in liquidation or receivership - under a general security arrangement.

The amount owing to preferential creditors - including Inland Revenue - were also yet to be confirmed.

Most of the business and assets of the group had been sold to Downers in March 2017 for $60m, resulting in a winding down of the company's New Zealand construction activities.

The remaining rump of the company suffered a blow in the High Court in May, when it was ruled H Construction North Island must pay $13.4m over leaky building defects at Botany Downs Secondary College. The company had previously been paid $28m to building the school.

Liquidators said they would review related-party transactions, and the sale to Downer, as part of their investigation.

More information about the financial structure of Hawkins is expected to come next week when receivers McGrathNicol - appointed to much of the group in May - publish their first report.

Weekend Herald requests for comment to David McConnell, director of all of the companies in the group and its parent, were not returned.

But in a statement last month McConnell said the wind-down following the sale to Downer had been complicated by taking longer than expected to receive final payments for the groups' final projects, "creating a cash-flow issue that resulted in Orange-H Group being placed in receivership."

McConnell claimed there were significant assets in the group - including $20m owed by customers and $14m in cash-backed bonds - and his family's interests were not expected to receive any recovery from the action.

Hawkins was founded in 1946 in Hamilton, and by 1951 was listed on the NZX. In 1983 it merged with McConnell Dowell, and was taken private in 1994 after being taken over by McConnell family interests.