The Supreme Court on Friday asked political parties taking part in ongoing elections to provide details of funds received through electoral bonds .
In 2017, India proposed these bonds as a transparent way for political funding.
Prime Minister Narendra Modi's ruling Bharatiya Janata Party has received most of the funds flowing through the bonds, according to a court filing by the Election Commission.
Chief Justice Ranjan Gogoi said political parties must submit in a sealed cover precise details of their funding by May 15.
Modi is seeking a second term in an mammoth election that began on Thursday.
For detailed coverage about this topic: Electoral bonds