The U.S. government had ambitious plans to help earthquake-ravaged Haiti where more than three-fourths of the population lives on less than $2 a day — construction of 15,000 homes in the poorest country in the Western Hemisphere.

Disputes over land rights, inaccurate estimates and higher costs have forced the U.S. Agency for International Development to drastically scale back those plans and left members of Congress questioning whether American tax dollars are delivering the help first promised after the Jan. 12, 2010 earthquake.

The Government Accountability Office, in a report released on Tuesday, found that as of March 2013 the agency had disbursed only 31 percent of $651 million despite the government's insistence that it was committed to Haiti's reconstruction. The GAO also found that "a substantial amount of progress on project activities remains to be completed."

Instead of 15,000 homes for 75,000 to 90,000 beneficiaries, the agency plans to build 2,649 homes for some 13,200 to 15,900 beneficiaries. In fact, the agency is expected to build 906 houses and non-government agencies and other partners are on tap to construct 1,743 homes.

Among the problems causing delays and cost increases was acquiring the land titles to build as well as the Haitian government's demand that the homes have flush toilets. One difficulty was that before the January 2010 earthquake, Haiti had no wastewater treatment plants.

Since then, a temporary facility has been constructed at one location and a permanent plant built near the capital city of Port-au-Prince though it's unclear whether the facilities can serve the homes.

The earthquake displaced some 2 million people, killed about 230,000 and injured 300,000. Congress voted to provide $1.14 billion in reconstruction funds, including $651 million for the agency which provides U.S. economic and humanitarian assistance worldwide.

Rep. Ileana Ros-Lehtinen, R-Fla., who requested the report when she led the House Foreign Affairs Committee last year, said the findings were "alarming and showcases the need to further investigate and ensure that U.S. taxpayer dollars are not being wasted or abused in Haiti."

The committee plans to send a bipartisan delegation of staff members to Haiti, said the current chairman, Rep. Ed Royce, R-Calif.

Rep. Eliot Engel of New York, the panel's top Democrat, said the GAO found a "significant and sobering disconnect between what was originally promised for the Haitian people, and what it appears USAID is now prepared to deliver."

The leaders of the committee released the report.