The Democratic Alliance (DA) says that the Electoral Commission of South Africa (IEC) must explain how embattled Tshwane politician Sheila Senkubuge was voted into council allegedly before she became a naturalised citizen.This, after a private citizen laid charges against Senkubuge questioning whether she was eligible to hold a council seat, claiming she initially held permanent residency at the time of her appointment, before she became a naturalised citizen, the party confirmed.If correct, the letter questions how both her party, the DA, and the IEC did not pick this up, and wanted a probe into the facts of the matter.Senkubuge has since resigned amid another debacle involving her and Tshwane Mayor Stevens Mokgalapa allegedly being caught on a leaked "sex scandal" recording."The IEC must explain its processes in this regard and the law must follow its course," Gauteng provincial leader John Moody said on Saturday.Resignation letterHe made the statement after Senkubuge resigned as a City of Tshwane Member of the Mayoral Committee (MMC).News24 has reached out to IEC spokesperson Kate Bapela for comment. The story will be updated once comment is received.On Sunday, the IEC responded, saying Senkubuge was a verified citizen at the time of her appointment, according to the voters' roll.UPDATE: Senkubuge was a citizen at time of Tshwane appointment, according to voters' roll - IECMokgalapa has been placed on special leave since Thursday, after being embroiled in the leaked recording scandal with Senkubuge.READ: Embattled DA politician Sheila Senkubuge resigns from Tshwane city councilIn her resignation letter, which News24 has seen, Senkubuge said that despite her work successes, there were efforts to personally drag her name."In light of recent events, and despite the many successes, it has become clear that attempts to vilify me are taking focus away from the purpose of my role in office. This will in turn inevitably affect service delivery to our residents," she wrote.When asked if her resignation was linked to the leaked recording, Moody said: "It is up to her at the end of the day, she needs to face whatever action she needs to face."*This story has been updated to include the IEC's response.