CROWN POINT | The U.S. Attorney's office subpoenaed six years worth of records Wednesday from the Lake County Health Department as part of a federal investigation, a county official said.

Officials from the U.S. Environmental Protection Agency and the Indiana Department of Environmental Management carted boxes and crates of materials from county offices Wednesday afternoon but would not disclose what was in them.

Assistant county attorney Joe Irak said the county received a subpoena requesting every record from the county's lab since 2003, but acting U.S. Attorney David Capp said he could neither confirm nor deny any details of any ongoing investigation.

County officials confirmed last week the EPA is investigating the health department, probing allegations that employees there altered drinking-water tests.

No public health threat has been identified, but the EPA is examining the scope of the allegedly false reports, filed by two staff members whom county officials say have since been fired.

EPA and IDEM officials confirmed they were at the department Wednesday but declined to say why they were there or what they may have taken from the office.

The county shuttered its lab in late February, citing a lack of funds to upgrade it. Officials later acknowledged concerns about the lab's reports also prompted the closure.

An April inspection by the State Department of Health - which certifies water-testing labs - listed more than 50 problems with the county lab, calling it ill-equipped to test samples.

The lab got low marks for potentially nonsterile tools, questionable record-keeping and unsanitary conditions during renovation, according to the state report.

The poor report prompted the county to rescind its lab's state certification.

"The deficiencies noted were of such a nature the laboratory could not continue under their current certification," state agency spokesman Ken Severson said in an e-mail. "Before any action could be taken, the laboratory requested that its certification be withdrawn due its inability to fully address the deficiencies cited in the report."

Despite multiple attempts, The Times was unable to reach Lake County Health Officer Dr. Susan Best for comment.