A married couple and prominent builder charged with defrauding the Commonwealth of up to $71 million have denied allegations against them.

Michael Buckley, 41, Dallas Adrian Wynne, 48, and his wife Natalie Wynne, 40, are accused of conspiring together to influence the awarding of building contracts to M + J Builders, and a subsidiary company some of them owned.

In their first hearing last November, prosecutor Ingrid Ibbett said the Crown was content — providing strong conditions were imposed — with Mr and Ms Wynne being granted bail with the same lengthy conditions as their co-accused, the only difference being the couple could not contact Mr Buckley and his wife, Jessica Buckley, who was also later charged with the same offence as her husband and the Wynnes.

Experienced lawyer Matthew Hubber was now representing Mr Buckley, a co-owner of M + J Builders with his wife Jessica.

He said on Tuesday the prosecution had not shown how it intended to prove the fraud allegations.

Police allege Mr Wynne, a Department of Defence employee, leveraged his role to influence contracts and tenders for M + J Builders.

The defendants have been under tight conditions since being granted bail in November, while AFP officers continue to investigate allegations of fraud.

None of the defendants were required at the Darwin courthouse when their matters returned on Tuesday morning, represented instead by their lawyers.

Mr Buckley was initially represented by well-known NT lawyer Peter Maley, before engaging the services of Mr Hubber.

Proceedings before Judge David Woodroffe on Tuesday began with prosecutor Ms Ibbett requesting a 10-week adjournment, as "outstanding" material had yet to be handed to the defence.

"There are a lot of electronic devices seized on the day (of arrest) that require review among other items," she said.

The lengthy adjournment was due, she said, to the "large amount of material" expected to be passed over.

While defence counsels took no issue with the request, Mr Hubber used the opportunity to put "a couple of points" on the record.

"The allegations have been reported widely in the media," he said.

"[My clients] deny the allegations and, concerningly, it's not apparent from the prosecution summary — or the evidence served so far — how the prosecution intends to prove these allegations."

Mr Hubber asked that no further adjournment be granted.

A preliminary examination mention is scheduled for April 28, with the defendants excused and their current bail conditions remaining intact.

Meanwhile, the prominent NT builder continues to operate from its office in Winnellie, Darwin, with M + J Builders staff in branded work clothing seen coming and going from their office hub off Coonawarra Road.