Image caption At the heart of the Casement Park controversy are concerns over safety

More detail about the wrangling behind-the-scenes over safety concerns at the proposed new Casement Park stadium in west Belfast has been revealed.

The safety expert, who claimed he was bullied by a Stormont department, took a grievance case against his boss at Sport NI over the way his complaints were handled.

At the heart of the Casement Park controversy are concerns over safety.

Could the 38,000-capacity stadium be evacuated safely in an emergency?

Safety expert Paul Scott has been arguing that it cannot. He claims attempts were made to bully him into changing his mind.

Image caption Safety expert Paul Scott made his concerns public

Last month, he made his concerns public. The Department of Culture, Arts and Lesiure (DCAL), immediately announced an investigation.

However, there has also been a separate investigation into complaints that Mr Scott made about how his boss at Sport NI handled his concerns.

According to documents given to MLAs last month, he won a grievance case against Sport NI chief executive Antoinette McKeown.

In December, Mr Scott wrote to the board of Sport NI, telling them in detail about one meeting to discuss Casement where, he said, he and he and a colleague had been "met with a barrage of abuse from DCAL".

Then, he wrote formally to Ms McKeown and referred to having "raised concerns about the pressure being asserted on me to approve the proposals for Casement Park".

Image caption Mr Scott won a grievance case against Sport NI chief executive Antoinette McKeown

However, he was not happy with how she dealt with the matter and told her: "I do not believe that you have handled my complaint appropriately" and subsequently launched a formal grievance procedure.

The investigation into his complaint concluded that it was "valid" and that his grievance had been upheld.

Image caption Mr McAdam said Ms McKeown believes she acted in good faith

In response, Kevin McAdam from the union, Unite, representing Ms McKeown and speaking on her behalf said: "Antoinette McKeown believes she acted in good faith, in the proper manner with the structures that are in Sport NI.

"Had she been allowed to manage as expected, then the organisation would be in a healthier, better place now.

"She has given a matter of record as to how she dealt with it and the organisation itself has said no action is required."

Mr McAdam also confirmed that Ms McKeown is currently suspended from her role.

"Antoinette is currently the chief executive officer, she is currently under suspension pending investigation into leadership issues, not necessarily related to her, but to the organisation in general," he said.

The stadium project has been plagued by difficulties, so much so that there are doubts over whether it will ever be built.

One of the big issues surrounds the emergency exits.

Image caption Emergency exits are one of the big issues

The design of the stadium needs to be able to cope with more than 30,000 people being able to get out quickly and safely, that would include ensuring that areas like turnstiles do not become over-crowded and dangerous.

The GAA is working on a new planning application. It has also denied any of its representatives were involved in bullying.

At the same time, DCAL said its investigation into Mr Scott's allegations of bullying continues.

It is expected to be completed next month.