The FBI is investigating a Republican sheriff running unopposed in the battleground state of Ohio, but officials won’t explain the reason why.

FBI Special Agent Vickie Anderson confirmed to WLIO that federal agents carried out a search warrant at the Allen County Sheriff’s Office on Wednesday, when the news site captured officials removing items from the building in Lima.

Sheriff Sam Crish, a Republican who was first elected in 2008 and is running unopposed this year, has not been at the sheriff’s office in recent days, and Chief Deputy Jim Everett has taken over daily operations, according to the news site.

“I am not at liberty to go into details on that,” Anderson said of the investigation, according to the Lima News. “Some of the information may be unsealed next week.”

Anderson would not confirm that Crish is the subject of the investigation, but noted that there have been no arrests.

Lima attorney Michael Rumor said he’s representing Crish during the investigation but declined to comment further.

“We are representing Sam,” he said. “That is the extent of what I can say.”

The Lima News confirmed that Crish has not submitted a resignation to the Allen County Sheriff’s Office or the Allen County Board of Elections.

“We want the citizens of Allen County to know no one man runs the sheriff’s office, and the rank and file is in place to keep the citizens of Allen County safe,” said Lt. Matt Treglia, now second in command. “It’s business as usual.”

Treglia would not comment on the investigation or his boss’ whereabouts.

The sheriff’s office’s most recent high profile case involved eight heroin overdoses in Allen County over two days late last month. That investigation, followed a wave of 174 heroin overdoses in the Cincinnati area over a week’s time, the Associated Press reports.

The FBI investigation in Lima follows similar investigations of Republican sheriffs in Arizona and Oklahoma.

Sheriff Joe Arpaio, of Maricopa County, Arizona, an outspoken supporter of Republican presidential candidate Donald Trump known for his tough stance on immigration, as well as Oklahoma’s Love County Sheriff Marion Russell have also faced FBI investigations.