Donations received in form of electoral bonds were not included in the filing.
From disbursing Rs 25.11 crore to political parties in 2014-2015, the Tata group is learnt to have contributed Rs about Rs 600 crore towards the 2019 Lok Sabha election.
The ruling party received Rs 742 crore in 2018-19, a rise of 70 per cent from the previous year.
'Rather than encouraging transparency, the opacity of electoral bonds adds to the murkiness,' argues Amit Tandon.