South Africa's official opposition party, Democratic Alliance (DA), on Thursday denied media reports that it would charge Cape Town Mayor Patricia de Lille over her appearance at a memorial service for the late Winnie Madikizela-Mandela.

De Lille's appearance at the event caused some controversy when she fondly spoke of the late struggle icon and her encouragement of the mayor, who faces a disciplinary hearing from her party.

The DA said in a statement it expected De Lille to inform them she was attending the memorial, as a courtesy.

"The DA regularly receives invitations from other political parties to address events or rallies and this is not in any way unusual. However, we do ask that the individual concerned informs the Party leadership," the statement said.

"The DA has, along with the nation, been mourning the death of Mrs Madikizela-Mandela and refuses to be drawn into mud-slinging in her name. It is simply inappropriate."

De Lille has consistently denied allegations of misconduct as mayor, and has accused party leaders of trying to discredit her, calling it a witchhunt.

During the memorial service in Brandfort in the Free State province on Wednesday, De Lille recalled the last time Madikizela-Mandela called her in December last year.

"She said....'those boys don't know who they dealing with'."