WASHINGTON — The Agriculture Department sent $1.1 billion in farm payments to more than 170,000 dead people over a seven-year period, congressional investigators say.

The findings by the Government Accountability Office were released yesterday as the House prepared to debate and pass farm legislation this week that would govern subsidies and the department's programs for the next five years.

GAO auditors reviewed payments from 1999 through 2005 in the report, which was requested by Iowa Sen. Charles Grassley, senior Republican on the Senate Finance Committee.

The auditors said they found that the department has not been conducting the necessary checks to ensure that subsidy payments are proper.