Joseph Duggar's In-Laws to Be Questioned in Child Molestation Case

Joseph Duggar's attorneys wants to question his in-laws as they fight criminal charges related to allegations he molested a 9-year-old girl ... TMZ has learned.

According to new legal docs, obtained by TMZ, Kendra Duggar's parents, Paul and Christina Caldwell, are scheduled to be questioned under oath on September 14 at the State Attorney's Office in Panama City, Florida.

Investigator Darrell "Chase" Norris is also set to be deposed, while a man named Thomas Lowe will be questioned later that afternoon. The notice says the testimony is being gathered for discovery and possibly to use at trial.

The U.S. Sun was the first to report this news.

The Caldwells were apparently close friends with the Duggar family before Kendra married Joseph in 2017 ... but the relationship has reportedly fallen apart amid his mounting legal troubles.

As TMZ previously reported ... Kendra allegedly stopped communicating with her parents after Joseph's arrest, while the Caldwells moved out of their home and considered leaving the state.

The Caldwells previously said they were "troubled and heartbroken" by the allegations and stood behind the alleged victim.

Joseph was arrested in March after a girl told investigators he allegedly molested her during a 2020 family vacation in Panama City Beach, when she was 9 years old. Police say Joseph later admitted his actions to the girl's father.

The former "19 Kids and Counting" star pleaded not guilty and was released on $600,000 bond. A judge has barred him from having unsupervised contact with minors ... including the four children he shares with Kendra.