Adani agreed to cover Isaac Regional Council's costs to employ four extra staff to handle work relating to the company's controversial Carmichael coal mine.

The Crime and Corruption Commission said it would not formally investigate Adani or the central Queensland council because "there is no evidence that raises a reasonable suspicion of corrupt conduct".

It also said there was no conflict of interest over the arrangement and staff were employed on merit, without Adani's input.

"In the absence of any evidence to support allegations of corrupt conduct relating to the agreement or the hiring of staff, the CCC does not intend to take any further action in relation to this matter," the watchdog said in a statement on Friday.

In defending the agreement last month, Isaac Mayor Anne Baker said it ensured ratepayers were not burdened by costs incurred as a result of a project's development.

She welcomed the issue being settled.

"For us, cost recovery through infrastructure agreements with resource companies is business as usual," Ms Baker said on Friday.

"We have been an open book on this issue and were absolutely confident that our arrangement was appropriate, legal and within the bounds of the state-mandated requirements."

Australian Associated Press