Twenty-seven regional political parties received Rs 887.551 crore, or 76.14% of their total declared income, from unknown sources in 2021-’22, a report by the Association for Democratic Reform said on Tuesday.

The report also found that Rs 827.76 crore, or 93.26%, of the income from unknown sources came from electoral bonds.

Electoral bonds are monetary instruments that citizens or corporate groups can buy from a bank and give to a political party, which is then free to redeem them for money. The Centre first introduced electoral bonds in January 2018.

The Association for Democratic Reforms defined income from known sources as that for which donor details are available through contribution reports submitted to the Election Commission of India. Income from unknown sources is that which is declared in the annual audit reports, but the source of income is not given.

Currently, political parties have to disclose all donations above Rs 20,000 in their contribution reports.

The 27 regional parties analysed in the report on Monday had declared a total income of Rs 1,165.57 crore in 2021-’22. Of this, Rs 145.42 crore, or 12.48%, was from known donors.

The Dravida Munnetra Kazhagam had the highest income from unknown sources (Rs 306.02 crore), followed by the Biju Janata Dal (Rs 291.09 crore), the Bharat Rashtra Samithi (Rs 153.03 crore), the Yuvajana Sramika Rythu Congress (Rs 60.01 crore) and the Janata Dal (United), which received Rs 48.36 crore from unknown sources.