DALLAS (AP) — An apartment building in New Orleans links two central characters in the financial demise of a troubled government school bus agency in Dallas, raising ethical questions over rules governing conduct between school district officials and their vendors.

An investigation by KXAS-TV and the Dallas Morning News shows former Dallas County Schools Superintendent Rick Sorrells used a luxury vacation apartment in the New Orleans French Quarter since 2014. The neighboring apartment was used by Robert Leonard, the CEO of the company DCS partnered with on a risky business venture.

The educational agency partnered with Force Multiplier Solutions on a school bus camera venture that used millions of dollars and put DCS on the brink of financial collapse earlier this year.

The attorney for the New Orleans building's owner, Louis Faust, said Leonard is no longer a tenant and Sorrells' lease ends in November.

The neighboring apartments raised new questions about whether the relationship between Sorrells and Leonard went beyond the bounds of ethical guidelines governing the conduct of school officials and vendors.

"Certainly anyone who had a vetting responsibility for those contracts would be very uncomfortable with this kind of personal relationships overlaying a business relationship," said Cal Jillson, a political science professor at Southern Methodist University.

While Sorrells was superintendent, his agency's board approved contracts with Force Multiplier Solutions that directed more than $70 million of public money to the company.

DCS is currently conducting an internal audit on business dealings between the agency and Force.

Sorrells lost his superintendent position this year amid the agency's financial troubles but will remain on the payroll until December as part of a retirement deal with the agency.

He said Leonard wasn't involved in his family getting the apartment. An attorney for Leonard said he's advised his client to not speak on the matter.

Don Southerland, a former FBI agent, said investigators need to ask more questions about the apartments because they could provide more insight into the relationship between the two men involved in a business arrangement that ended unsuccessfully.

"There's a lot of smoke around this building," Southerland said.