City of Cape Town spokesperson, Priya Reddy, said a summons meant for the company was still being put together.
"The prosecutor will be drawing up the document tomorrow [Tuesday]," said Reddy.
Asked when exactly the summons would be served on the company, Reddy said: "It will happen soon."
She would not divulge any further details on the company.
While it was still unclear who contracted Independent Outdoor Media to erect the banner, the ANC has accused the DA of having a hand in the incident.
Moloto Mothapo, spokesperson for the office of the ANC chief whip, said, "The DA has been pulling all the stops to defend and justify racism and promotion of apartheid amongst its membership, and has thus sought to create an expensive stunt to deflect from the negative attention it has been suffering."
He also criticised the City of Cape Town for allegedly doing nothing to stop the illegal act from being carried out.
"Instead of dispatching the Metro Police to stop the public violation of its laws, all it did was to issue a media statement," Mothapo said.