The U.S. Postal Service said it is cooperating with a U.S. government investigation into a former postal worker's claim that he has been seriously ill for more than a year after he says he came in contact with a suspicious package at the Florida facility where he worked.

The U.S. Occupational Safety and Health Administration last month opened a probe into the incident in early 2011 involving former Orlando sorting facility supervisor Jeffrey Lill, Michael D'Aquino, a spokesman for OSHA's southeast regional office, said on Monday.

Lill's claims came to light after a report by the Florida Center for Investigative Reporting detailed his situation in several newspapers, including The Miami Herald.

Lill told Reuters a wet package he handled indicated it was sent from an address in Yemen to a local address in Orlando. He has since experienced memory loss, chronic nausea, shaking and other problems, but says the Postal Service has not told him what chemicals he may have come into contact with.

"I just want to get better. I don't care about anyone getting in trouble on their side," said Lill, who had to stop working and, in September 2011, moved in with his mother, who lives in a suburb of Rochester, New York.

In an interview, Lill's eyes appeared unfocused and he occasionally seemed to be in pain. His hands curled inward, and he scratched his forearms.

"The only thing I care about is them sending a piece of paper that says 'Here's what was in the box, and here's what your doctors need to run traces against, and it'll clear you up and make you feel better,'" Lill said.

The Postal Service declined to comment beyond confirming that it is participating in the OSHA investigation.

According to documents Lill's uncle provided to Reuters, an attorney for the Postal Service has been in contact with Lill's attorney.

That letter stated that the agency has records of a spill that occurred at the Orlando facility on February 2, 2011, in which no injuries were reported.

The USPS attorney, Isabel M. Robison, wrote that the Postal Service does not know of a spill on February 4, 2011, the day Lill's attorney said the incident occurred, according to the document viewed by Reuters.

The Postal Service and Lill's attorney and family offer different accounts of the events in the documents, and many details are still unclear.

For instance, a postal official wrote in a letter to Lill that he continued to work for five months after the incident is said to have occurred, and said there is no record that Lill reported a work-related injury or illness.

Lill's mother, Janet Vieau, responded in a letter that he did continue to work, then reported the illness to a supervisor when his doctors began considering exposure to a toxic substance as a potential source of his problems.

A spokesman for U.S. Representative Ann Marie Buerkle, who represents the New York district that is now Lill's home, said the congresswoman has been communicating with postal officials to determine what happened.