Fire has gutted the fifth floor of the Job 600 building which is still under construction.
The post independence edifice, which is right behind Parliament House, is scheduled to be completed by August this year. It will serve as offices for Members of Parliament and their research assistants.
Eyewitnesses say the fire started around 5:30 pm and the experience of personnel from the Ghana National Fire Service, helped in bringing it under control.
The cause of the fire outbreak is still unclear and no injury or loss of life has so far been reported.
The imposing edifice was constructed during the administration of Osagyefo Dr Kwame Nkrumah, Ghana’s First President to accommodate participants attending the OAU (now African Union) Conference held in Accra in 1965.