The director of the Missouri state health department admitted to keeping a spreadsheet that monitored the menstrual periods of Planned Parenthood patients at an administrative hearing Tuesday over whether the clinic can remain open.

Dr. Randall Williams testified in front of the state's administrative hearing commission that he directed the state’s main investigator to compile a list of patients using accessible medical records that included dates of their last menstrual periods, according to the Kansas City Star. In reviewing the data, the investigation was able to identify patients who had had "failed medical abortions."

Williams added that the investigation into Planned Parenthood, which stands as the state’s last abortion clinic, began after health officials found evidence of a failed abortion that did not have an accompanying complication report, the newspaper reported.

The spreadsheet containing the menstrual period information was found during the course of legal discovery and was scrutinized by Planned Parenthood attorneys.

According to state officials, an investigation using the period spreadsheet found four patients who had "failed abortions" at the clinic, and who had to visit Planned Parenthood multiple times. The incidents raised “grave concerns” and prompted the health department to cancel the health center's abortion license in June.

The Missouri Department of Health and Senior Services also cited an inspection conducted in March that found other safety related problems.

Planned Parenthood refuted those claims saying state health officials singled out four abortions from thousands the clinic has conducted for an investigation, and argued that the clinic had not violated any safety protocols. They added that the licensing issue is part of a greater anti-abortion effort by the state's administration.

Planned Parenthood has been locked with the state in a legal standoff before an administrative commissioner since Monday over whether the clinic’s license should be reinstated. While the hearing will last five days, a ruling is not expected until at least early next year.

Planned Parenthood initially challenged the license revocation in Circuit Court over the summer, and although a judge temporarily sided with the clinic, he sent the final determination down to the Administrative Hearing Commission.

Missouri stands as one of the most restrictive states for abortion access despite a federal judge blocking a bill signed by Missouri Gov. Mike Parson which outlaws abortions after eight weeks of pregnancy, including in cases of rape or incest.