"This forms 66.34 per cent of the total income of national parties added together during 2016-17," Delhi-based think-tank Association for Democratic Reforms (ADR) said in a report released today.
Indian National Congress (INC) followed with Rs 2.25 billion -- 14.45 per cent of the total income, it said, adding that CPI has declared the lowest income of Rs 20.8 million which forms a mere 0.13 per cent.
The data has been compiled from Income Tax returns filed by the parties across the country.
The seven national parties declared a total expenditure of Rs 12.28 billion, the report added.
The report further said that 70 per cent of the total income of BSP, 31 per cent of the total income of BJP and CPI and 6 per cent of the total income of CPM during 2016-17 was declared unspent.
BSP's total income was Rs 1.73 billion during 2016-17, while its total expenditure was Rs 518 million.
Between 2015-16 and 2016-17, the income of BJP increased by 81.18 per cent from Rs 5.70 billion to Rs 10.34 billion, while that of INC decreased by 14 per cent from Rs 2.61 billion to Rs 2.25 billion.
Income of BSP increased by 266.32 per cent from Rs 473.8 billion during 2015-16 to Rs 1.73 billion in 2016-17, while that of NCP increased by 88.63 per cent from Rs 91.37 billion during 2015-16 to Rs 172.35 billion in 2016-17.
The report further noted that between 2015-16 and 2016-17, the income of AITC decreased by 81.52 per cent and that of CPM fell by 6.72 per cent.
BJP and Congress have declared donations/ contributions as one of their three main sources of income.
"Grants/donations/contributions of Rs 9.97 billion declared by BJP formed 96.41 per cent of the total income of the party during 2016-17. Declaration of Rs 1.15 billion under revenue from the issuance of coupons by INC forms the top most income of the party, contributing 51.32 per cent of the total income of the party during 2016-17," ADR said.
The maximum expenditure for BJP during 2016-17 was towards election/general propaganda, which amounted to Rs 606.64 crore followed by expenses towards the administrative cost, Rs 697.8 billion.
INC spent the maximum Rs 1.49 billion on election expenditure followed by the expenditure of Rs 1.15 billion on administrative and general expenses, the report said.
Seven national parties have collected maximum 74.98 per cent (Rs 11.69 billion) income from voluntary contributions for 2016-17.
During 2016-17, national parties received Rs 1.28 billion income from interest from banks and FD.
The report added that 7.98 per cent or Rs 1.24 billion was the income generated through revenue from issuance of coupons by national parties during 2016-17.
ADR had earlier released the Analysis of Income & Expenditure of National Political Parties for FY2016-2017 on February 7, 2018 without the details of BJP and INC as the audit reports of these parties were not available in the public domain.
The due date for submission of annual audited accounts for the parties was October 30, 2017. BJP submitted its audited report on February 8, 2018 (delayed by 99 days) and Congress on March 19, 2018 (delayed by 138 days).
In its observation, ADR said that four out of seven national parties (BJP, INC, NCP and CPI) have consistently delayed submitting their audit reports for the past five years.