The national parties have collected more than Rs 15,077.97 crore from unknown sources between 2004-05 and 2020-21, an analysis by the poll rights body -- Association for Democratic Reforms, showed.

The total income of national and regional parties from unknown sources for 2020-21 stands at Rs 690.67 crore.

ADR considered eight national parties and 27 regional parties for this analysis.

The national parties comprised the Bharatiya Janata Party, Indian National Congress, All India Trinamool Congress, Community Party of India-Marxist, Nationalist Congress Party, Bahujan Samaj Party, Communist Party of India and National People's Party.

The regional parties included Aam Aadmi Party, Asom Gana Parishad, All India Anna Dravida Munnetra Kazhagam, All India Forward Bloc, All India Majlis-E-Ittehadul Muslimeen, All India United Democratic Front, Biju Janata Dal, Communist Party of India-Marxist Leninist-Liberation, Desiya Murpokku Dravida Kazhagam, Dravida Munnetra Kazhagam, Goa Forward Party, Janata Dal-Secular, Janata Dal-United, Jharkhand Mukti Morcha, Kerala Congress-Mani, Maharashtra Navnirman Sena, Nationalist Democratic Progressive Party, Naga People's Front, Paattali Makkal Katchi, Rashtriya Lok Dal, Shiromani Akali Dal, Sikkim Democratic Front, Shiv Sena, Sikkim Krantikari Morcha, Telugu Desam Party, Telangana Rashtra Samithi and YSR-Congress.

The analysis conducted on the basis of the parties' Income Tax Returns and donations statements filed with the Election Commission of India found that between FY 2004-05 and 2020-21, the national parties have collected Rs 15,077.97 crore from unknown sources.

"For FY 2020-21, eight national political parties have declared Rs 426.74 crore income from unknown sources and 27 regional parties received Rs 263.928 crore income from unknown sources," it said.

During FY 2020-21, Congress declared Rs 178.782 crore as income from unknown sources which is 41.89 per cent of the total income of national parties from unknown sources (Rs 426.742 crore)," the analysis said.

The BJP declared Rs 100.502 crore as income from unknown sources which is 23.55 per cent of the total income of national parties from unknown sources.

The top five regional parties in terms of unknown income are YSR-Congress with Rs 96.2507 crore, DMK with Rs 80.02 crore, BJD with Rs 67 crore, MNS with Rs 5.773 crore and AAP with Rs 5.4 crore.

As many as 47.06 per cent of the total Rs 690.67 cr account for the income from electoral bonds.

The ADR said the combined income of Congress and NCP from the sale of coupons between FY 2004-05 and 2020-21 stands at Rs 4,261.83 crore.

There are reporting discrepancies in the audit and contribution reports of seven political parties for FY 2020-21.

These seven parties include AITC, CPI, AAP, SAD, KC-M, AIFB and AIUDF.