Charity federations under the supervision of civil affairs departments managed to raise about one quarter of the country's total charitable donations last year, exerting a strong influence but lacking transparency, a study shows.

In 2011, charity federations nationwide collected over 20.3 billion yuan ($3.18 billion) in donations, with the China Charity Federation, a non-profit social group, topping the list with 6.5 billion yuan, according to a report on China's charities released Saturday by the China Charity and Donation Information Center (CCDIC) under the Ministry of Civil Affairs.

The number is down 15.9 percent from the previous year, according to the center.

For these federations, administrative expenditure accounts for less than 0.6 percent of the total expenditure in 2010, much lower than the 1.87 percent figure for foundations, the report shows. Many of them also receive government funding.

By June, there were over 1,900 charity federations above county level. Surveys of 30 federations at provincial level or above showed that 29 directors have worked in the government, one third are civil servants, and nearly 90 percent are of ministerial level, the Beijing News reported.

The strong official backgrounds of these organs appeared to have drawn more public scrutiny of its handling of donations and information transparency, after the nation's philanthropic sector took a hit following a slew of scandals.

The China Charity Federation was accused of selling pumped-up invoices that enabled donors to dodge taxes in exchange for much smaller donations in August 2011. The federation later denied the accusation but admitted that they needed to improve their transparency, media reported.

Statistics complied by the CCDIC shows that donations to the federation dropped 23.8 percent in 2011 compared with the previous year.

It is important that the government-backed charities have a sense of the crisis and take the initiative to gradually transform themselves, said Gao Huajun, executive vice dean of Philanthropy Research Institute at Beijing Normal University.

"They should be more innovative in their work and gradually detach themselves from the government," he said.