The train, consisting of four locomotives and 268 wagons filled with iron ore, was deliberately derailed by BHP's remote operations centre on Monday.
"We will be liaising with our customers in relation to our contractual commitments over this period", she added.
BHP confirms the suspension of normal train operations but all of its main mines remain operational.
Australia is one of the world's major sources of iron ore.
Transport Minister Rita Saffioti said the National Rail Safety Regulator had been informed and was investigating.
"A lot of people were expecting some kind of rally in the fourth quarter, but this is getting increasingly unlikely", Leszczynski said.
The train had four locomotives and 268 wagons, the ATSB said.
BHP is planning to draw from its stockpiles at Port Hedland as it repairs its rail service, The West Australian reported.
The incident resulted in a mangled wreck among piles of iron ore spanning more than 1.5 kilometres.
More than 130 workers have been deployed to fix the track and recover the wreckage, with BHP saying it would be removed "over the next few days".
BHP said recovering the train and fixing the track - a key access route for the enormous mining facility - will take around a week. "We can not speculate on the outcome of the investigation", BHP said.
"We can not speculate on the outcome of the investigation, however we are working with the appropriate authorities and our focus remains on the safe recovery of our operations", the BHP spokeswoman said.