About 93 per cent of the total voluntary contributions above Rs 20,000 received by the six national political parties between 2016-17 and 2017-18 came from corporates and business houses, a report says.

The ruling Bharatiya Janata Party (BJP) got the major chunk -- Rs 915.59 crore from 1,731 corporate donors from the total Rs 1,059 crore these parties received, reveals the report released by the Association for Democratic Reforms (ADR) on Tuesday.

The Congress received Rs 55.36 crore from 151 corporate donors while the Nationalist Congress Party (NCP) got Rs 7.74 crore from 23 donors.

"During FY 2016-17 and FY 2017-18, BJP's and Congress' voluntary contributions above Rs 20,000 from corporate/business houses is 94 per cent and 81 per cent respectively," said the report.

The Communist Party of India (CPI) got the least corporate donations at 2 per cent.

The ADR also highlighted that various sectors of business houses between 2012-13 and 2017-18 donated a total of Rs 1,941.95 crore, or 91.17 per cent of the total contribution from known sources amounting to Rs 2,123 crore.

"National parties have received the maximum corporate donations of Rs 573.18 crore in FY 2014-15 (when the Lok Sabha elections were held), followed by FY 2016-17 with Rs 563.19 crore and FY 2017-18 with Rs 421.99 crore," read the report.

"Between FY 2012-13 and 2017-18, donations from corporates to national parties increased by 414 per cent, with a major drop in the percentage of corporate donations in FY 2015-16."

The donations reduced by 25.07 per cent in 2016-17 and 2017-18, ADR said.

"Between FY 2012-13 and 2017-18, the BJP received the maximum corporate donations of Rs 1,621.40 crore, constituting 83.49 per cent of the total corporate donations in the six years," it said.

Prudent/Satya Electoral Trust was the top donor to two of the national parties.

"The Trust donated a total of 46 times in two years, amounting to Rs 429.42 crore," said the report.

It said the BJP declared receiving Rs 405.52 crore in 33 donations while the Congress was the recipient of Rs 23.90 crore of funds in 13 donations from Prudent/Satya Electoral Trust.

Bhadram Janhit Shalika Trust was the second highest corporate donor to the BJP and the Congress, donating 10 times, a total amount of Rs 41 crore.

The ADR said electoral trusts were the biggest donors to the national parties, contributing a total of Rs 488.42 crore.

Real estate sector was the second highest overall contributor in 2016-17, contributing a total of Rs 49.94 crore. In 2017-18, rhw manufacturing sector was the second highest overall contributor (Rs 74.74 crore).

Between 2016-17 and 2017-18, the BJP and the Congress received the maximum contributions from Electoral Trusts.

The BJP got the most, at Rs 458.02 crore, followed by the Congress (Rs 29.40 crore).

The BJP received the highest donations from all 15 sectors including manufacturing (Rs 107.54 crore), real estate (Rs 88.57 crore), mining, construction, exports and imports (Rs 57.40 crore).

A total of 916 donations through which national parties received Rs 120.14 crore do not have address details in the contribution form, the ADR said.

National parties have received Rs 2.59 crore from 76 donations which did not have PAN details in the contribution form and 98 per cent of such donations without PAN and address details worth Rs 2.50 crore went to the BJP.

The ADR also said the six national parties reported receiving 347 donations amounting to Rs 22.59 crore from corporate entities which had zero Internet presence or if they did there was ambiguity about the nature of their work.