THE FBI is investigating a major theft ring in which Philadelphia Housing Authority workers allegedly stole millions of dollars worth of building materials, including hardwood oak floors and stainless-steel kitchen appliances, and either fenced them or installed them in private homes.

Federal investigators have spent more than two years combing through thousands of Home Depot invoices billed to PHA. They are examining whether the materials went into the homes of PHA employees or those connected to them, according to sources close to the investigation.

At least one PHA employee has been fired in connection with the case.

In one instance, FBI agents tracked truckloads of Home Depot merchandise to a West Oak Lane property owned by a cocaine dealer (see story next page).

In 2008, when the investigation was in its infancy, then-PHA executive director Carl R. Greene attempted to thwart the probe by trying to fire two PHA police officers, according to sources close to the investigation. The officers had alerted the Philadelphia District Attorney's Office and U.S. Attorney's Office about the possible theft.

Yesterday, PHA spokeswoman Nichole Tillman declined to comment, as did Greene's attorney, Clifford Haines. FBI spokesman J.J. Klaver also declined to comment.

Greene was fired last week by the PHA board for failing to disclose settlements worth hundreds of thousands of dollars with women who filed sexual-harassment complaints against him.

Citing the open criminal investigation, Tillman said that PHA could not provide the Daily News with copies of subpoenas related to the probe.

Home Depot spokeswoman Jen King deferred questions to PHA officials and federal authorities.

The investigation began in July 2008, when Philadelphia police raided a North Philadelphia chop shop.

Inside a garage on 7th Street near Venango, police found a stolen 2000 Mitsubishi and a stockpile of building materials labeled with "Home Depot bills made out to PHA," according to a July 15, 2008, search warrant.

Police seized four bundles of 2-by-4s, 11 bundles of plywood and six bundles of drywall "stolen from the Philadelphia Housing Authority," according to the search warrant.

The district attorney charged the garage owner, Joseph Rios, with receiving stolen property and criminal mischief. But prosecutors later dropped the charges, court records show.

Rios, who owns an auto-body shop and towing company in the Northeast, told the Daily News that at the time of the raid he was leasing his garage to another tenant. He said he couldn't recall the name of the tenant and no longer had the lease paperwork. The tenant never returned to the property, he said.

"Everybody disappeared," Rios said.

Detective John Logan contacted PHA police, who began to check hundreds of Home Depot invoices and quickly suspected theft that had gone on for years.

Many of the invoices listed one of three people as authorizing the PHA purchases for curbside delivery: Richard A. Perri, a longtime PHA materials coordinator; and two PHA contractors, carpenters Michael Kinkade and Nicholas Cionci.

Kinkade and Perri declined to comment. Cionci did not return two phone calls from the Daily News.

Sources close to the investigation say that the feds are trying to determine whether the three ordered the materials or if other people used their names.

PHA fired Perri in late 2008, after investigators suspected that he had used PHA materials to renovate his Northeast ranchhouse. He had added a second floor with three large bedrooms and a master suite with vaulted ceilings, sources close to the investigation said.

He sold his house in June for $345,000.

The Daily News obtained several 2007 Home Depot invoices that list Perri as ordering the purchases. This small sampling of invoices are for thousands of dollars, charged to the agency's account for PHA's "scattered sites." But most of the addresses were not PHA properties. The items include oak hardwood floors, suede cowhide gloves, flowers and pruning shears - items that would be unusual for a PHA property.

Investigators believe that in some cases the drop-off addresses were decoys, and that corrupt PHA workers called Home Depot at the last minute to reroute the materials to a different house, sources close to the investigation said.

FBI agents have questioned Perri about his home renovations and Kinkade about the Home Depot purchases.

Soon after PHA police started to investigate the Home Depot invoices, Greene ordered that the files be shipped to the Ballard Spahr law firm.

Greene hired Ballard Spahr attorney Kenya Mann Faulkner, a former federal prosecutor, to investigate the case.

PHA managers said they were summoned to Ballard Spahr to examine stacks of Home Depot invoices, most of which named Cionci and Kinkade. When they arrived at the law firm, Daniel Quimby, PHA general manager of maintenance, was there.

Quimby was the direct supervisor of Perri, Kinkade and Cionci. Quimby was in charge of authorizing PHA purchases from Home Depot. Quimby retired earlier this year and went to work for General Asphalt Paving Co., owned by the family of city GOP power broker Michael Meehan.

Quimby did not return calls to his homes in Philadelphia and the Poconos.

At the Ballard Spahr meeting, Quimby implicated PHA managers who were in charge of maintenance at scattered sites. The managers said they told Quimby that they knew nothing about the Home Depot orders and had not approved them, according to some of those present at the meeting.

The managers told Quimby that none of the materials, including a stainless-steel refrigerator and a microwave, had gone into any PHA homes.

In early 2009, when Mann Faulker was deep into the investigation, Greene fired her and replaced her with Jim Eisenhower, of Schnader Harrison, according to a source familiar with the investigation.

Eisenhower declined to comment on what had become of the internal investigation.