WICHITA — Kansas legislative leaders are demanding the Education Department suspend the state's top school finance official, alleging he unlawfully allocated as much as $405 million in transportation funds in 45 years.

Dale Dennis, the deputy education commissioner, said he has been calculating transportation payments to school districts exactly the way he was directed by the legislative leadership decades ago — and that to do otherwise would have discriminated against districts, including Wichita, with high population density.

Senate President Susan Wagle and House Speaker Ron Ryckman detailed allegations against Dennis in a letter to Jim Porter, chairman of the state Board of Education.

The complaints about Dennis come in the midst of controversial school finance decisions the Legislature has to make this year. The state Supreme Court has ruled the Legislature has unconstitutionally underfunded schools and ordered lawmakers to fix it.

The letter obtained by the Wichita Eagle late Wednesday spins off of a Legislative Post Audit report that said the Education Department exceeded its authority by setting minimum funding levels for transportation.

"Mr. Dennis has admitted to LPA and others that he knew Kansas statute did not authorize a minimum per-student funding level for transportation weighting," the letter said. "Regardless, he knowingly directed KSDE to distribute these unauthorized payments for decades based on a conversation with Senator Charles Angell, a former member of Senate leadership who left legislative service in 1984."

Angell, a Republican from Plains, served from 1973 to 1984 and was Senate vice president for the last four years of his tenure.

"Even if this conversation did occur (which we cannot verify because Sen. Angell passed away in 2014), KSDE has no right to violate state law based on the request of a state legislator or any other person," the Wagle-Ryckman letter said.

The letter went on to estimate the unauthorized spending at more than $300 million if it began in 1984, and $405 million if it started when the Legislature removed transportation minimums from the state education funding formula in 1973.

Although they wrote they did not question Dennis' honesty, the two legislative leaders asked Porter to launch a detailed forensic audit and implied the attorney general's office also will be asked to take a look.

They said they have lost faith in Dennis and his immediate staff and asked that they be placed on paid leave until the audit and investigation are finished.

Dennis said no one ever has questioned the way the calculations were made or asked to change it until now, despite multiple court cases over school funding, numerous legislative hearings where the formula was explained, and a large audit of school finances in 2006.

"It's never been mentioned before, to my knowledge," Dennis said.

Dennis also said he doesn't know how Wagle and Ryckman calculated it had cost the state as much as $405 million.

"I don't know how they arrived at that number," he said.

The issue centers on a math concept called "line of best fit," which is used to calculate trends among divergent amounts of transportation funding, Dennis said.

He said legislative leaders told him they wanted it done a certain way so urban districts wouldn't get shortchanged on bus money.

"This is what they told me. They said: 'Our definition of the line of best fit is, you take the upper, those high-density districts, eight to 10 of them, throw out the high and low and pick the median and you freeze it there so they're not discriminated against,' " Dennis said. "That's how I was told to do that, and that's in the early '80s. That minimum amount was put in there at the request of legislative leadership."

He said the department occasionally seeks clarification from legislative leaders on interpreting the laws they pass.

"A member of the legislative staff drew it out for me, showed me how to do it, what to do, and said, 'That's our definition of a best fit,' and said, 'Do you understand it?' And I said 'Yes, sir.' And it's been in effect for 30-some years."