Sonia Gandhi, the president of India’s opposition Congress party, is being questioned by a government agency in connection with a corruption case.
She and her son Rahul Gandhi have been accused of misusing party funds to acquire valuable real estate through a convoluted financial deal.
The Gandhis deny all the allegations.
They accuse the governing Bharatiya Janata Party (BJP) of using federal law enforcement agencies for political vendetta.
On Thursday, Congress workers held protests as Mrs Gandhi left for the office of the Enforcement Directorate (ED), which investigates financial crimes.
She arrived at the ED office accompanied by Rahul Gandhi who was questioned in the same case in June. Mrs Gandhi was initially called for questioning at the same time, but her summons had to be deferred after she tested positive for Covid-19.
The 75-year-old leader was admitted to hospital and was discharged later in June.
This is the first time that Mrs Gandhi will be questioned by a federal law enforcement agency. BJP leaders have denied accusations by Congress party leaders that they are misusing federal institutions to settle political scores.