P_Wei/iStock(WASHINGTON) -- Federal officials have launched an investigation into allegations that the Department of Veterans Affairs is putting its health care workers in danger as they continue to work on the front lines fighting the novel coronavirus, according to a Department of Labor letter obtained by ABC News.

The Occupational Safety and Health Administration (OSHA) investigation comes in response to a VA union complaint last week that medical workers who were exposed to infected patients did not receive coronavirus testing and lacked sufficient protective equipment, including N95 respirators, eye protection, face masks and gowns.

Hundreds of VA medical center employees have tested positive for COVID-19 and eight have died after contracting the disease, according to the department.

The numbers of infected employees continue to grow along with the rising case count among the nation's veterans. So far, 284 veterans seeking treatment at VA-run facilities have died while the number of confirmed positive cases reached nearly 5,000 on Thursday.

The OSHA investigation comes as VA supervisors continue to reassess their equipment stockpiles amid nation-wide shortages.

"All VA facilities are equipped with essential items and supplies, and we are continually monitoring the status of those items to ensure a robust supply chain," Veterans Affairs press secretary Christina Noel said in a statement to ABC News on Tuesday.

Although department leaders have denied equipment shortages, the director of VA's health care system -- obtained by ABC News -- acknowledges a prior department policy of only providing one mask to employees each week unless they had direct contact with a confirmed COVID-19 patient.

VA now appears to be increasing the number of health workers that are allowed protective masks. All employees at VA community centers and special care units will receive one mask each day, Veterans Health Administration chief Richard Stone said in the Wednesday night email to VHA employees.

Noel confirmed on Thursday the agency had been conserving PPE more strictly until now. She said the agency had been following the Centers for Disease Control and Prevention guidance that all health centers use "contingency strategies" to conserve equipment.

The CDC's guidance from April 3 says U.S. health care facilities should "carefully prioritize" PPE use, noting that they should generally consider limiting respirators to doctors and nurses who directly come in contact with airborne disease.

"VA's PPE conservation posture is precisely why the department has not encountered any PPE shortages that have negatively impacted patient care or employee safety," Noel said Thursday. "What's more, VA today was able to return to a contingency -- rather than crisis-capacity posture for PPE use."

The federal agency entered the crisis with severe staffing shortages and vacancies at its highest ranks. VA's hospital network reported more than 44,000 vacancies at the end of 2019, raising questions about its preparedness to handle the coronavirus crisis.

In a letter to Vice President Mike Pence on Thursday, House Democrats on the Veterans Affairs Committee said the White House had blocked VA from disclosing its protective equipment policy.

"These additional bureaucratic delays have created a logjam in which the documentation we have repeatedly requested has not been provided, and the lack of specificity in VA's ongoing briefings for the Committee, not only poses risks of potential harm to veterans, but also leads us to a simple conclusion -- your administration has hamstrung VA's ability to ensure Congress is fully informed," the Democrats wrote in the letter released by committee Chairman Mark Takano, D-Calif.

Copyright © 2020, ABC Audio. All rights reserved.