A Pennsylvania state senator arrested on charges of child pornography resigned Wednesday.

Sen. Michael Folmer, 63, was charged with sexual abuse of children, possession of child pornography, and criminal use of a communication facility after child pornography images were found on his phone, Pennsylvania Attorney General Josh Shapiro announced Tuesday.

On Wednesday, Gov. Tom Wolf called on Folmer, a Republican representing Lebanon County, to resign, calling the charges against the lawmaker "disgusting and beyond comprehension."

Later on Wednesday, leaders of the state Senate said in a statement that Folmer resigned, NBC Philadelphia reported.

A criminal complaint on Folmer said that the National Center for Missing and Exploited Children received a tip in February from the social media site Tumblr that a user had downloaded at least one image containing child pornography in late 2017.

Pennsylvania state Sen. Mike Folmer, R-Lebanon, speaks at a Capitol news conference in Harrisburg, Pa. Marc Levy / AP file

An investigation began in March and eventually led to the home of Folmer.

The state attorney general's child predator section, Lebanon city police, and the U.S. Department of Homeland Security executed a search warrant at the lawmaker's home and for his cellphone on Tuesday and found child pornography images on the phone.

Folmer admitted to investigators that he had used his Tumblr blog to receive child pornography, according to the criminal complaint. He said that "he had been dealing with some personal problems/issues."

A spokeswoman for the attorney general's office said Folmer's bail has been set at $25,000. It is unclear if he has posted it.

The senator was elected to a fourth term in November. He was instrumental in swinging conservative votes behind a bill to legalize medical marijuana in 2016, according to a profile on his website.

He opposed legislation that would have lifted legal barriers for victims of long-ago child sexual abuse from suing institutions, according to NBC Philadelphia.

Folmer is married and has two adult children and seven grandchildren, his online profile says. Neither Folmer nor his office responded to requests for comment Wednesday morning.