The top leader of Tennessee's Department of Safety & Homeland Security made a contribution to Republican gubernatorial nominee Bill Lee last month while his agency was conducting an investigation into a trooper who divulged information about Lee's opponent.

Commissioner David Purkey made the $1,000 donation to Lee on Sept. 20 amid an internal investigation involving a Tennessee Highway Patrol trooper who shared confidential information about Democrat Karl Dean's schedule while talking with Lee's RV driver.

In response to questions about Purkey's campaign donation, department spokeswoman Megan Buell said that "any personal political activity related to the Governor’s race was done in accordance with state law."

Lee's campaign also released a statement.

"Bill is proud to have the generous support of more than 6,100 donors across Tennessee," Lee spokeswoman Laine Arnold said.

On Friday, Dean's campaign announced he was calling for an independent review in the situation by the Tennessee Bureau of Investigation. The state agency said earlier this month it was not investigating the incident.

Department declines to say when Purkey reached out to campaigns

The trooper in question, Anthony Bull, was assigned Sept. 7 to help on the security details of both Lee and Dean during campaign stops in East Tennessee.

Bull inadvertently divulged to Lee's RV driver the location of a Dean campaign stop later that day, violating the confidentiality agreement he signed, according to department of safety records.

Bull told the driver about Dean attending a Muslim event, and later the Lee campaign jokingly suggested that a second trooper take a photo of Dean, according to documents detailing the department's investigation. Earlier this month, a Lee spokeswoman said the candidate had no recollection of the conversations.

Following the investigation, Purkey informed Bull in writing on Sept. 25 that he would be suspended without pay for one day for violating department policies, including a nondisclosure agreement Bull had signed.

In a statement Oct. 9, Purkey told the USA TODAY NETWORK - Tennessee that he had apologized to both campaigns for Bull's actions. But the department has repeatedly declined to say when Purkey reached out to the campaigns about the incident.

Dean said that his campaign was never informed by the department about the breach in confidentiality.

Instead, Dean said it was a whistleblower inside the department who notified his campaign about the incident, prompting Dean staffers to set up a meeting with Purkey Sept. 19 to discuss the breach.

The next day, Purkey made the donation while serving as a co-host for a Lee fundraiser held for supporters in Hamblen and Jefferson counties.

Purkey, a Morristown native, served as mayor of Hamblen County for four terms, until 2010.

Gov. Bill Haslam appointed him commissioner of the Department of Safety and Homeland Security in 2016. Prior to that, upon taking office in 2011, Haslam first appointed Purkey to be homeland security adviser and assistant commissioner of the department.

According to campaign finance disclosures, Purkey donated $5,500 to Haslam between 2009 and 2014.

Reach Natalie Allison at nallison@tennessean.com. Follow her on Twitter at @natalie_allison.