MUMBAI (REUTERS) - An aide to an Indian ruling party candidate, who recently defeated Congress party chief Rahul Gandhi for a seat in parliament, was shot dead overnight, police said on Sunday (May 26).

Mr Surendra Singh was an aide to Ms Smriti Irani, a former television actress and dogged minister in Prime Minister Narendra Modi's Cabinet.

In one of the biggest upsets of the election that handed Mr Modi's Hindu nationalist Bharatiya Janata Party (BJP) a second term, Ms Irani beat Mr Gandhi in the Amethi constituency, which had been held by his family almost continuously for the last four decades, in the northern state of Uttar Pradesh.

Mr Singh worked closely with Ms Irani and distributed sweets and paraded with celebrating supporters last Friday, a day after the election results, his relatives told Reuters partner ANI.

He had gone to sleep on the veranda outside his home when unidentified gunmen shot him, Amethi Superintendent of Police Rajesh Kumar told Reuters on Sunday.

"Some unknown people have fired on him and he died due to firearm injury," Superintendent Kumar said.

Seven people have been arrested, he said, adding that it was too early to draw conclusions about a motive.

Requests for comment from two BJP spokesmen went unanswered.

An official at the BJP headquarters in Uttar Pradesh was unable to immediately provide any information.