Mr Gandhi denies the accusations made against him
A grandson of the ex-Indian PM Indira Gandhi has been detained under a federal law for inciting religious tensions during the election campaign.
Authorities in Uttar Pradesh state imposed the National Security Act (NSA) on Varun Gandhi, a candidate of the main opposition Bharatiya Janata Party.
Under the NSA, a person can be detained up to one year without bail.
Mr Gandhi has denied making inflammatory speeches and said a recording of them had been "doctored".
The Election Commission has said it was convinced that footage of Mr Gandhi's speech had "not been tampered with, doctored or morphed as alleged by the respondent".
Mr Gandhi is now lodged in a prison in Pilibhit where he surrendered on Saturday.
A senior official of the Uttar Pradesh government said that the NSA had been invoked in Mr Gandhi's case on "charges of inciting communal passion by making provocative and inflammatory speeches during [election campaign] meetings".
The decision to impose the federal law late on Sunday came a day after Mr Gandhi surrendered to a local court after a criminal case was lodged against him for making the speeches.
His arrest was marked by violent protest by his supporters.
On Sunday, three new cases were lodged against Mr Gandhi and his supporters including attempt to murder, rioting, destruction of public property and preventing government officials from their duty.
The footage of Mr Gandhi's rallies on 6 and 8 March in Pilibhit have been broadcast on Indian television.
The BJP has said Mr Gandhi will be its candidate despite an advice from the federal election authorities to drop him.
Mr Gandhi cannot be barred from contesting elections unless he is convicted or found guilty by courts and sentenced for at least two years in jail.
Mr Gandhi is the son of Sanjay Gandhi, Indira Gandhi's younger son who was killed in a plane crash.
Although he is a descendant of the influential Nehru-Gandhi dynasty, Mr Gandhi belongs to a side of the family that has disowned them.