The clean-up of the wreckage of a derailed train in southern NSW is yet to begin more than a week after the incident, with businesses reporting tens of thousands of dollars in lost revenue as a result.  

Four locomotives and 16 wagons were knocked off the tracks when a train and truck collided at a level crossing north of Wagga Wagga last week, with the three drivers involved sustaining minor injuries.

The timeline for the reopening of the track has since blown out from five days to nearly three weeks, with Transport for NSW estimating it won't be repaired until March 27.  

The prolonged closure has caused logistic mayhem for businesses along the freight line, such as Croker Grain in Marrar, about 35 kilometres north of Wagga Wagga.

The company uses the rail about five times a week to transport its stockpiles of wheat, barley and grain to shipping docks in Melbourne.

Trade manager Lyndon Benecke said the closure has had a "massive impact" and stalled export.

He estimated it would cost the small company up to $150,000.

"You've got two or three weeks when you're out and you've got staff that you can't just force to go on holidays," he said.

Coolamon Shire Council general manager Tony Donoghue said many businesses were now having to send their stock over 100 kilometres west, to connect to the rail network at Griffith.

"It's definitely a longer trip and an inconvenience for the companies, but ultimately we're lucky we're on a loop," Mr Donoghue said.

Administrative dispute behind standstill

In a statement, a Transport for NSW spokesperson said the agency was working with all parties to restore the track as quickly as possible, but that weather had delayed the process.

But a Southern Shorthaul Railroad, which owns the derailed train, said the company was denied access to the track to start the clean-up due to an administrative dispute.

Spokesperson Jason Ferguson said his company has an existing track access agreement with UGL Regional Linx, which operates and maintains the Country Regional Network on behalf of Transport for NSW.

But he said they were asked to sign a new legal document, taking on additional liabilities, in order to retrieve the wreckage.

"We believe that's a significant overstep and not covered by the [current] access agreement," he said.

Transport for NSW did not respond directly to questions about the access dispute but said the track clean up will begin on Friday.

Mr Ferguson said the company has been granted access since being contacted by the ABC.