Adani has admitted to an “administrative error” after it failed to declare track clearing and exploratory drilling it conducted in June to environmental regulators.

The Indian mining giant on Tuesday admitted it had failed to declare some activity at its Carmichael mine site in the Galilee Basin, which occurred in the last three weeks of the 2017/18 financial year.

It comes after environmental activists earlier this month published drone and satellite pictures that showed track clearing and bore drilling at the site, which they claimed was in breach of the company’s environmental conditions.

The Queensland Department of Environment and Science said last week it would investigate the claims. However, Adani has now given all material to the department, claiming an administrative error is to blame for it not being handed over sooner.

“Critically, we can confirm that all physical works that have occurred onsite to date are Stage 1 project activities related to geological sampling and groundwater investigations, which are permitted under our Environmental Authority,” the company said in a statement on Tuesday.

“We have also made improvements to our procedures to ensure administrative errors of this nature do not occur in the future.”

The error comes as activists ramp up pressure on the miner over its use of water, with fears its bores could affect the Great Artesian Basin.

There’s also fears Adani could take billions of litres of water from a nearby river system for use in its proposed mine.

But the federal government says a broad assessment of the Indian mining giant’s plan to pump 12.5 billion litres of water from the Suttor River each year and pipe it to its Carmichael coalmine project does not apply.

The Australian Conservation Foundation and Lock the Gate say Environment Minister Melissa Price did not apply an assessment known as the water trigger to the mining giant’s proposed water infrastructure in the Galilee Basin.

The water trigger allows the impact of large coalmine developments on water supplies to be assessed at a national level.

Lock the Gate says Ms Price will not apply the water trigger to Adani’s North Galilee Water Scheme project.

“This is another special deal for Adani that puts our water resources at risk during a terrible drought and hangs Queensland graziers and communities out to dry,” spokeswoman Carmel Flint said.

The Environment Department says the proposed infrastructure is not captured by the water trigger because it is not directly involved in digging coal from the ground.