Substandard conditions found at the main US army medical centre in Washington were not an isolated incident, a key congressman has said.
Former patients and relatives testified at the hearing
The problem extends "beyond the walls" of the Walter Reed medical centre, said John Tierney as his congressional panel held its first hearing into the case.
There have been reports of soldiers living in rat-infested buildings.
The scandal has already led to the resignation of the civilian head of the army and top generals.
Mr Tierney, a Democrat, chairs the national security panel of the House Oversight and Government Reform Committee, which began its hearings on Monday.
"There appears to be a pattern developing here... First deny then try to cover up, then designate a fall guy. In this case I've concerns that the army is literally trying to whitewash over the problems," he said.
The hearing also heard from veterans who had stayed at the Walter Reed Army Medical Center.
One, John Shannon, told the committee that there was black mould in the rooms.
"It wasn't fit for anybody to live in a room like that," he said.
Annette McLeod, the wife of a former patient, told the committee staff at the hospital had given her husband "zero percent".
"You need to fix the system," she said. "If you're good enough to go, you're good enough to be taken care of when you leave here."
At the weekend President Bush said he was "deeply troubled" by the reports of poor living conditions at the centre - where soldiers returning from Iraq and Afghanistan were treated.
Articles in the Washington Post newspaper said patients lived in rat-infested rooms and complained of bureaucracy.
Army Secretary Francis Harvey and the head of the medical centre, Maj Gen George Weightman, have resigned over the allegations.
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