FLINT, MI -- Michigan's public health director and chief medical executive have been charged with criminal wrongdoing related to the Flint water crisis, moving an investigation by state Attorney General Bill Schuette closer than ever to Gov. Rick Snyder.

Genesee District Judge David Guinn authorized charges Wednesday, June 14, for Department of Health and Human Services Director Nick Lyon and Chief Medical Executive Dr. Eden Wells.

Lyon, appointed by Snyder to lead DHHS in April 2015, was charged with one count of involuntary manslaughter, a 15-year felony.

He also faces a single count of misconduct in office.

Wells, who has worked in public health in the state for more than a decade, faces charges of obstruction of justice and lying to a police officer.

Attorney General Bill Schuette has scheduled a news conference to discuss his water investigation, which has resulted in 15 criminal prosecutions of current or former government employees, at 11 a.m. Wednesday in Flint.

Lyon becomes the highest-ranking state employee to face criminal charges for his role in the water crisis.

In 2016, he was identified as a target of Flint water prosecutors and his attorney told MLive-The Flint Journal previously that his client received a subpoena for a felony criminal case though he wasn't initially charged.

Prior to his appointment to serve in the governor's cabinet, the Yale University graduate had led a major division within DHHS.

A task force appointed by Snyder has said that Lyon was aware of suspicions that the Flint River was the source of a deadly outbreak of Legionnaires' disease in Genesee County by January 2015, just eight months after it became the city's water source.

Snyder has said he was not told of that suspected link until a full year later, allowing Flint emergency managers to continue using the river.

Wells has said that DHHS missed opportunities to address Legionnaires' but did not attempt to withhold information.

Wells was named by Snyder to be Flint's drinking water public health adviser after the governor acknowledged rising levels of lead and the potential connection between the use of the river and Legionnaires'.

DHHS officials initially concluded that spikes in blood lead levels in children immediately after the city changed its water source to the Flint River were seasonal and not related to water.

The department also initially questioned the findings by a Hurley Medical Center pediatrician, Dr. Mona Hanna-Attisha, who in September 2015 reported blood lead levels of children in some parts of the city tripled after the switch to river water.

Lyon said in an email in advance of a news conference by Hanna-Attisha, "I would like to make a strong statement with a demonstration of proof that the lead blood levels seen are not out of the ordinary and are attributable to seasonal fluctuations."

Wells later endorsed Hanna-Attisha's work, agreeing that blood lead levels were rising among Flint children under 5 years old.

Snyder's Flint water task force concluded in its report to the governor that DHHS's "response to two public health concerns, related to lead exposure and cases of Legionella infection, did not meet the agency's own standard of performance" and was "fundamentally flawed."

Check back with Mlive.com for more information on this story as it develops.