Karen Whitmore was made redundant from her post as assistant director of organisation and governance at Middlesbrough Council in June.
Teesside Magistrates Court heard claims she was targeted for raising concerns about the sale of buildings for under the market value.
Ms Whitmore claims unfair dismissal.
The hearing was told of Ms Whitmore concerns over the council's sale of Grade I listed Acklam Hall.
She said that when she asked by external auditors to investigate the sale she was told officers had agreed a price reduction of £1.2m for the building.
Ms Whitmore was also told to hide the way it was handled because the then-mayor, Ray Mallon, did not want to be embarrassed, she claimed.
The tribunal was also told she raised concerns about selling Middlesbrough's Training and Development Centre to Mr Mallon's election agent, for £400,000 after an independent valuation was put at between £600,000 and £900,000.
She claimed she was bullied by the current chief executive, Tony Parkinson, undermined by the former chief executive, Mike Robinson, and her concerns and complaints were ignored by the mayor, David Budd.
All men contest the accusations, and the hearing continues.
A former senior council officer was "bullied and threatened" after refusing to cover up the way assets were sold off, an employment tribunal has heard.