Greene said he was emotionally undone by the lien, filed in December, which froze his bank account and meant he could not pay the mortgage.
The Inspector General's Office of the federal Department of Housing and Urban Development has also opened an investigation into PHA's use of stimulus funds for renovating 340 scattered-site vacant houses.
The program audit, started last month, involves the spending of $31 million in federal stimulus dollars.
The inspector general has subpoenaed the Social Security numbers of 28 employees, an unusual move PHA is challenging. It is not clear why the information is being sought, but in an interview Friday, Greene said he considered it an invasion of the employees' privacy.