In 2015-16, the Bharatiya Janata Party (BJP) raised 80.5 per cent of its total income from unknown sources while the Congress raised 71 per cent of its total income from unknown sources in the same period, a new report by Association for Democratic Reforms (ADR) has revealed.

BJP's total declared income was Rs 570.86 crore and Congress's income was Rs 261.56 crore. Out of its total income, the BJP collected Rs 460.78 crore from unknown sources and Congress party collected Rs 186.04 crore from unknown sources, the report said.

ADR analysed the income and expenditure data of national and regional political parties submitted to the Election Commission of India. "Unknown sources are income declared in the income tax returns, but without giving source of income from donations below Rs 20,000. Such sources include 'sale of coupons', 'relief fund', 'miscellaneous income', 'voluntary contributions', 'contribution from meetings/morchas' etc. The details of donors of such voluntary contributions are not available in the public domain," the ADR report said.

While voluntary contributions was the most preferred form of fundraising for the BJP, 'sale of coupons' was the most preferred form of fundraising for Congress party, the report said.

The report added that seven national parties raised a total of Rs 1,033.18 crore in 2015-16. Of this, parties spent Rs 754.45 crore and declared an unspent amount of Rs 278.73 crore.

The BJP had the highest income followed by the Congress, the Communist Party of India (Marxist) (Rs 107.48 crore), the Bahujan Samaj Party (Rs 47.39 crore), the Trinamool Congress (Rs 34.58 crore), the Nationalist Congress Party (Rs 9.14 crore) and the CPI (Rs 2.18 crore).

ADR also mentioned that compared that BJP's income during financial year 2014-15 was highest among all the National Parties. The party had declared a total income of Rs 970.43 cr and its income decreased by 41.17% to Rs 570.86 cr during financial year 2015-16.