Senior fire safety staff are putting together their findings after they looked into the cause of the fire that broke out at Parliament in Cape Town on Sunday.

Their findings will be handed over to the police, mayco member for safety and security JP Smith said.

The fire gutted the third floor of the Old Assembly building, including office space and the gymnasium. The roof of the Old Assembly building collapsed.

Parts of the ceiling at the New Assembly building, to which the fire spread, also collapsed. Extensive damage was caused to the National Assembly.

One of the aspects the fire safety officials will look into is how the fire spread from the Old Assembly to the New Assembly.

Smith says there could have been a second point of origin or the fire could have spread through the air-conditioning system.

"The aircon didn't switch off immediately because the electricity didn't switch off automatically. We had to manually switch off power to the precinct," Smith said. 

Initial findings pointed to potential maintenance issues in the building because some of the sprinklers were due for a maintenance service in 2020 and investigators were unable to find records confirming that the service was carried out, Smith said.

A 49-year-old man has been arrested in connection with the fire.

He is expected to appear in the Cape Town Magistrate's Court on Tuesday and faces charges under the National Key Point Act as well as counts of housebreaking, theft and arson. 

According to Hawks spokesperson Brigadier Nomthandazo Mbambo, the man was allegedly caught in possession of suspected stolen property by members of the Protection and Security Services after he gained unauthorised entry to the parliamentary precinct.

The findings will be key in efforts to establish whether he had any involvement in the fire, or if the fire was caused by an electrical fault.

Smith added that a fire at Parliament 10 months ago was due to an electrical fault.