Karen Whitmore claims she was "bullied and threatened" because she refused to turn a blind eye to the flawed way some of its buildings were sold off.
But, former chief executive Mike Robinson told the hearing Ms Whitmore was never asked to hide any facts.
Ms Whitmore, 49, was made redundant from her post as assistant director of organisation and governance in June.
Mr Robinson, who was chief executive between 2014 and 2016, said he had asked her to investigate the sale of council-owned Acklam Hall because there were accusations being made on social media and in the press.
A few weeks later she came back to him to say there had been no illegal action or corruption, he said.
The hearing had earlier been told about claims of a "laddish culture" at the council, with senior managers referring to women as "posh birds" and "fatties", but Mr Robinson said he did not recognise that language or behaviour.
He described the council as a "good place to work", and was unaware of any bullying that took place at the council during his time as chief executive.
The hearing, at Teesside Magistrates' Court, continues.
There was "no cover-up or corruption" at Middlesbrough Council, an employment tribunal has been told.