Mike Clevinger, a starting pitcher who signed with the Chicago White Sox earlier this offseason, is under investigation for violating Major League Baseball's domestic violence policy, a source told ESPN on Tuesday, confirming an initial report by The Athletic.

The investigation stems from allegations made by a woman, Olivia Finestead, who accused Clevinger of physical and emotional abuse toward his three children and their two mothers, herself included. She agreed to be named in an interview with The Athletic.

Finestead has been in touch with MLB investigators since last summer, when Clevinger was a member of the San Diego Padres, according to The Athletic, but mentioned her accusations in a series of stories on her Instagram account on Tuesday. In them, she accused Clevinger of "several acts of domestic violence and child abuse," including throwing "chew spit on a screaming infant child" and strangling her. The latter accusation was posted with a series of photos that alleged to be the result of violent acts committed by Clevinger, a 32-year-old who has been in the major leagues for seven years.

Clevinger's agent, Seth Levinson of ACES, could not immediately be reached for comment.

In a statement, the Padres said, "We are aware of MLB's investigation and completely support their efforts under the Joint Domestic Violence, Sexual Assault and Child Abuse policy. Due to the ongoing investigative process, we cannot comment any further at this time."

The White Sox signed Clevinger to a one-year, $12 million free agent contract near the end of November -- a deal that would pay him a base salary of $8 million in 2023 and included a $12 million mutual option, with a $4 million buyout, for 2024 -- and claimed they did not know about the allegations upon signing him.

"Major League Baseball and the Chicago White Sox take any and all allegations very seriously, and the White Sox are completely supportive of the Joint Domestic Violence, Sexual Assault and Child Abuse policy shared by MLB and the MLBPA," the White Sox said in a statement. "MLB opened an investigation after learning of these allegations. The White Sox were not aware of the allegations or the investigation at the time of his signing. The White Sox will refrain from comment until MLB's investigative process has reached its conclusion."

ESPN's Jesse Rogers contributed to this report.