WASHINGTON (Reuters) - A congressional panel probing the mishandling of dangerous pathogens at federal laboratories will try to determine if U.S. officials sought to cover up an incident involving deadly avian flu, its Republican chairman said on Tuesday.

Centers for Disease Control Biotechnology Core Facility (Building 23) is shown in Atlanta, Georgia June 20, 2014. REUTERS/Tami Chappell

Representative Tim Murphy said lawmakers will also look at whether lab workers face adequate “consequences” for failing to follow rules, and consider new legislation if penalties are lacking when actions endanger the public.

“Is it lax adherence to protocol? Are people ignoring protocol? Do they have this sense of mastery because they’ve been doing it so long,” said Murphy, who chairs the House Energy and Commerce Oversight and Investigations Subcommittee.

The panel is due to hear testimony on Wednesday from several witnesses, including Dr. Thomas Frieden, director of the U.S. Centers for Disease Control and Prevention (CDC).

The CDC has been engulfed in controversy since last month when officials revealed that 84 lab workers had potentially been exposed to live anthrax bacteria at its Atlanta campus. The public health agency later disclosed the discovery of vials containing smallpox at a National Institutes of Health facility outside Washington.

Murphy said the panel will also look closely at what many experts view as the most troubling incident, which occurred in March when workers at a high-security CDC influenza lab sent samples containing a dangerous strain of bird flu to counterparts at the U.S. Department of Agriculture. The incident was discovered in May but went unreported to senior agency leadership for six weeks.

“Was there a cover-up, particularly in the long delay in notifying the head of CDC? Were they hurtling through levels of bureaucracy? Was it incompetence? Or was it a cover-up?” Murphy said.

CDC spokesman Tom Skinner said: “There’s simply no explanation we have right now as to why it took so long for this incident to be reported.”

The CDC is investigating the incident and is determined to find out how it happened, Skinner said.

Murphy said the panel intends to scrutinize the actions of Frieden himself, whom the administration has put in charge of addressing the problems: “What actions did he take? Did he follow what the leader should do in terms of responsibility there.”

Lawmakers also hope to learn why a 2006 incident involving anthrax went unreported to Congress until last week when Frieden informed Murphy two days before revealing the mishap at a news conference.

The Pennsylvania congressman said the number of incidents have raised concern that the labs could be suffering from a culture of sloppiness and complaisance.