Investigations by the Homeland Security Department's (search) internal watchdog yielded the arrests of 146 workers and grant recipients and identified $18.5 million in unsupported costs during a six-month period that began last fall.

The semiannual report to Congress, issued by Homeland Security's inspector general, details findings of 325 internal investigations, audits and inspections between October 2004 and March 2005. A copy of the 54-page report, which has not yet been released publicly, was obtained Friday by The Associated Press.

Homeland Security "has made notable progress in securing the homeland and integrating its programs and operations," Acting Inspector General Richard L. Skinner (search) told Secretary Michael Chertoff (search) in a May 1 letter accompanying the report. "However, as you have repeatedly pointed out, further work is needed."

Homeland Security spokesman Brian Roehrkasse declined to comment.

Fines, restitutions and other funds recovered as a result of the investigations totaled $106 million over the six months, the report showed. Of $27.6 million in costs questioned by investigators, $18.5 million were found to be unsupported. Of the 146 arrests, 65 employees, contractors or grant recipients were indicted and 43 convicted. Additionally, 24 personnel actions were taken.

Among the findings:

Wasteful spending at the Transportation Security Operations Center included $500,000 in authorized decorative artwork and plants and the purchase of extravagant kitchen appliances and excessive fitness center equipment.

A contract worker with U.S. Immigration and Customs Enforcement sexually abused two male transgender detainees at a correctional facility in San Pedro, Calif. He was sentenced to 36 months probation and required to file as a sexual offender.

A U.S. Customs and Border Protection officer accepted bribes to, among other cases, help immigrants enter the country. He was indicted on counts of conspiracy, extortion, bribery and other charges and is on unpaid leave awaiting trial.

A Coast Guard employee stole alcohol worth thousands of dollars from a Coast Guard exchange warehouse. He was fired, sentenced to five years of probation and ordered to pay $30,000 in restitution