PORTLAND — A new judge will be presiding over the Kennebunk prostitution case.

Superior Court Chief Justice Thomas Humphrey on Monday assigned Justice Nancy Mills to the high-profile case of Mark Strong Sr., which is taking place in York County Superior Court. Mills normally sits in Cumberland and Kennebec counties.

Mills is the second judge who has been specially assigned to the case. The first, Justice Joyce Wheeler, recused herself last week. Wheeler did not provide a reason.

There was concern that if a judge who usually sits in York County knew any of the witnesses in the case, he or she might have to be recused from the case or any related cases, according to Mary Ann Lynch, a spokeswoman for the state judicial branch.

The existence of client records in the case has fueled speculation about who is on the list. Strong’s lawyer, Daniel Lilley, estimated that there were between 100 and 200 individuals, along with biographical information. He received the information Friday.

Strong, a 57-year-old Thomaston insurance agent and private investigator, is charged with promotion of prostitution, a misdemeanor. No one else has been charged in the case.

Strong was arrested in July, five months after police searched a fitness studio in Kennebunk, a nearby office space and the Wells home of Alexis Wright, the business’ owner. According to a police affidavit in support of Strong’s arrest, authorities found videotaped footage of Wright performing sexual acts with men, a ledger key containing prices for the acts, “meticulous” client records and evidence that Wright had asked Strong to run license-plate numbers.

Lilley has said that Strong was hired by Wright because she felt harassed by Kennebunk police. Strong later invested in what he believed was a legitimate business venture, according to Lilley.