AUSTIN (AP) - Federal authorities have determined an investigation by the U.S. Department of Veterans Affairs into the manipulation of wait times for Texas veterans seeking care was "deficient and unreasonable."

The U.S. Office of Special Counsel released a statement this week saying the investigation of scheduling manipulation at several Texas VA hospitals and clinics by the VA's Office of Inspector General "failed to appropriately address" whistleblower allegations. It found, for instance, the VA substantiated that improper scheduling occurred at facilities in Austin and San Antonio but didn't address whether that may have endangered public health and safety.

The OSC noted in its findings, which were first reported by the Austin American-Statesman, that a whistleblower at the VA medical center in Temple disclosed scheduling manipulation at her center and other facilities in the Central Texas Veterans Healthcare System. The Office of Inspector General did not substantiate the allegations by the whistleblower, but it also didn't address her contention that the VA categorized hundreds of health consultations as either scheduled or completed when they actually never were, according to the OSC.

In another instance, the OIG failed to address all of the allegations made by another whistleblower at the Temple center and failed to reconcile contradictory information. Similar problems also were found with other OIG reports.

The VA has subsequently promised to improve the way it conducts investigations into claims by whistleblowers.

"These employees raised important concerns about access to care issues within their hospitals and I applaud their efforts to improve care for veterans," Special Counsel Carolyn Lerner said in the OSC news release. "While these investigations failed to fully address the serious disclosures concerning the health and safety of our veterans, I am encouraged by the VA's commitment to improve its investigative processes moving forward."

An OSC spokesman did not return a call for comment Friday.

A report released in March by the OIG said that an internal VA investigation found that schedulers in Texas routinely misreported when patients actually wanted to see a doctor or get some other type of care, making it impossible to track delays in the care they received.

Similar problems have been found in other states. The office said in February that the OIG failed to adequately investigate claims that supervisors in Illinois and Louisiana directed mental health service employees to violate VA scheduling protocols. The OIG has moved to increase transparency amid pressure from Congress and state officials.

Scandal erupted in Phoenix nearly two years ago, following complaints that as many as 40 patients died while awaiting care at the city's VA hospital.

VA employees in Texas reported to investigators that they sometimes engaged in misleading scheduling at the behest of their supervisors. But supervisors and administrators at many facilities denied there was a systematic effort to manipulate wait time data. Some told investigators that schedulers may have misunderstood directives, while others said employees had since been retrained to correct the practice.