The man who brought the lawsuit, David Baker, was a foreman and driller responsible for operating a tunnelling machine at the time of his alleged injury.
He filed an application with the District Court in April, seeking compensation for injury from employer Skanska International Civil Engineering.
The application says he was injured at tunnel G, Tsing Yi, after inhaling 'oil gas/vapour and other chemicals', understood to be radon and carbon monoxide, on September 30 last year.
The company let Mr Baker go a month later. Skanska told him the termination was due to 'operational requirements'.
Mr Baker went to the Labour Tribunal to sue for wrongful dismissal in a separate legal action.
At a tribunal hearing last month, Skanska said it was impossible to consider compensation without a proper medical diagnosis of Mr Baker.
