Obama had previously promised during his presidential run in 2007 to cut out wealthy donors who buy their way into key posts.
But a a report has found that 200 donors were rewarded with key posts in the White House and lucrative federal contracts.
The donors are known as 'bundlers' as they use a loophole that prevents large individual donations and instead groups together a number of cash gifts from different people.
The scandal will raise fresh questions over Obama's credibility in the 2012 election campaign and his promise to reduce the practice of buying influence in politics.
The report by the Centre for Public Integrity shows how donors were given jobs in the Department of Justice, Department of Energy and the Federal Communications Commission, among other federal agencies, and been appointed to policy advisory commissions.
The study also discovered that one of the most prominent donor was Donald H. Gips who gave half-a-million dollars to Obama's election campaign in 2007.
Gips went on to take charge of hiring in the White House and was later named ambassador to South Africa.
His company, Level 3 Communications, was reportedly later granted $13.8m in stimulus contracts for broadband projects.
The report added that 80 per cent of Obama donors who raised $500,000 or more were given 'key administration posts'. Read More