US Congressional auditors have accused the development agency USAID of failing properly to administer its programme for promoting democracy in Cuba.
The US funds exile groups which then send surreptitious aid to Cuba
They said USAID had channelled tens of millions of dollars through exile groups in Miami, which were sometimes wasteful or kept questionable accounts.
The report said the organisations had sent items such as chocolate and cashmere jerseys to Cuba
Auditors also mentioned of the high cost of getting the donations to Cuba.
"We performed limited testing on 10 grantees and identified questionable expenditures and significant internal control weaknesses with three grantees that USAID had not detected," authors of the report said.
Correspondents say the findings will damage the reputation of Cuban-American organisations in Washington.
But critics contend that US government aid is more about winning votes from Florida exiles than really trying to change Cuba.
'Expense claims high'
The GAO report found that in the past decade USAID awarded 40 grants or co-operative agreements totalling $65m (£50.8m) and the State Department four grants worth $8m (£6.25m) to support democratic progress in Cuba.
USAID provided 385,000lbs (174,635 kilos) of medicine, food and clothing, more than 23,000 shortwave radios and millions of books, newsletters and other informational material.
It said dissidents interviewed by the GAO in Cuba said they appreciated the help.
But their report concludes that 30% of the exile groups who received USAID grants showed questionable expenditures.
The auditors also said the tender process was not transparent, and some expense claims seemed high.
The Bush administration recently promised to increase its assistance to promoting democracy in Cuba, but some congressmen say they will now push for hearings into the programme.
USAID says it has taken steps to comply with the report's recommendations.
Its chief financial officer, Lisa Fiely, in a letter to the GAO, said the agency took issue with some findings in the draft report, but would "seek to improve agency performance in managing, monitoring and evaluating this assistance".