IOWA CITY, Iowa (AP) — A safety regulator praised Tyson Foods for providing a written response two days after learning of a complaint alleging the coronavirus was spreading at its plant in Perry, Iowa, where a major outbreak was later confirmed.

Iowa Occupational Safety and Health records, reported Monday by The Associated Press, show the complaint was filed April 11, Iowa OSHA did not contact Tyson until April 20 and gave the company one week to respond.

The agency closed the inquiry April 28 after determining that Tyson's response outlining its safety efforts at the plant was satisfactory. No inspection was conducted. On May 5, the state announced 730 workers at the plant tested positive for coronavirus.

Tyson Foods released documents Tuesday showing it responded to the complaint April 22 with an undated letter from its plant manager — days earlier than reflected in OSHA's file.

An Iowa OSHA industrial hygienist thanked Tyson officials "for your diligence" in responding two days after being notified of the complaint, which alleged workers were not social distancing.

Tyson said that it had taken steps to protect Perry employees before then, including taking worker temperatures, encouraging them to wear face coverings and installing workstation dividers.

Gov. Kim Reynolds on Tuesday defended Iowa OSHA's response to the complaint, noting that it originally came in on a Saturday. She said the agency reached out to Tyson within one work week and determined the complaint didn't warrant a site visit because of the company's proactive measures.

"It appears that they followed normal and their appropriate process," she said.

U.S. Rep. Cindy Axne has demanded an investigation into OSHA's handling of the complaint.