Karnieka breathed her last at around 5.15 a.m. at Max Hospital, Saket. Her body will be taken to Ahmedabad, where her in laws reside, by flight at 10.30 a.m.
Karnika was earlier being treated in the US. During his visit to the US last September to meet his ailing daughter, Digvijaya had then confirmed his marriage to TV anchor Amrita Rai to a private TV channel.
Reports said the couple had put off celebrating the wedding in view of Karnika's deteriorating health. Amrita didn’t mind that as they never displayed their romantic liaison publicly.
The 68-year-old leader has one son and four daughters from his first wife Asha, who died in 2013.
Congress president Sonia Gandhi and vice-president Rahul Gandhi are expected to visit Digvijaya Singh's residence.