The controversial practice of having “ghost teachers” in public schools is haunting another Pennsylvania school district.

A lawsuit was recently filed against the Reading School District in eastern Pennsylvania, alleging that so-called ghost teachers have been paid more than $500,000, essentially to skip teaching classes and instead work full time for the local teachers’ union, the Reading Education Association (REA).

Under current state law, a collective bargaining agreement between a union and a school district can require the district to allow teachers to work full time for the union while still drawing a teacher’s salary and benefits. Such ghost teachers are also paid by their union.

The lawsuit’s plaintiff, Americans for Fair Treatment (AFT), is seeking to end the practice of ghost teaching in Reading. The group claims tax dollars are illegally being given to members of the REA. The AFT filed the lawsuit with assistance from the Fairness Center, a watchdog group.

“I think this has been off people’s radars for a while,” Karin Sweigart, the AFT’s deputy general counsel, said to Fox News. “Unless taxpayers were specific in requesting information on where their money was being allocated, they would not know about these salaries for ghost teachers.”

Sweigart and the AFT point out the district laid off 100 teachers along with hundreds of other employees in 2012 -- even while the Reading School District continued paying the salary of REA President Mitch Hettinger, who has not taught in a classroom since 2013.

“These teachers were forced from their classrooms while their union president [Hettinger] continued to receive full salary and benefits,” Sweigart said.

In the 2015-16 academic year Hettinger's salary and benefits, as a teacher, came to $131,000 — nearly 10 times the average per capita income of Reading residents — while working full time for the union, according to the Fairness Center.

Hettinger is also scheduled to retire this year, which means he will collect a pension based on his current teacher's compensation.

“In addition to siphoning money from the district to pay their salaries, Reading’s ghost teachers have been illegally boosting their pensions while working for the union,” Sweigart said. “That’s why, separate from this lawsuit, the Fairness Center has filed a formal complaint on behalf of a Public School Employees’ Retirement System (PSERS) member and Americans for Fair Treatment, asking PSERS to revoke any unearned pension credits from Reading ghost teachers.”

Officials for the Reading School District, as well as Hettinger, did not respond to requests for comment.

The litigation mirrors legislative action on the controversy. Republican lawmakers in Pennsylvania have voted in favor of a bill that would stop the state’s public school ghost teachers from collecting a paycheck from districts within the state.

The legislation, re-introduced by Republican state Sen. Patrick Stefano, would bar public school districts from allowing educators to take time away from teaching to work for local or statewide teachers unions in areas like personnel disputes and professional development -- while accruing salaries, benefits and pensions from the school district.

The Commonwealth Foundation, a Pennsylvania-based think tank, issued a report recently that found that more than 20 percent of Pennsylvania’s 500 school districts authorize full-time ghost teachers, according to a statewide survey of school district collective bargaining agreements.

The issue at Reading School District is similar to a lawsuit that was filed in the Allentown (Pennsylvania) School District last year, which led to the pension credits of current and former union presidents being revoked.

“Anytime taxpayer dollars are being steered out of the classroom it’s an unfair thing,” former Allentown School Board member Scott Armstrong, who was also a plaintiff in the suit, tells Fox News. “These kids need all the resources they can get.”

“I took the issue to the rest of the board and [initially] no one wanted to take action.”

Armstrong adds that while a decision was made, nothing has been put into effect in the Allentown School District thus far.

“The situation has not been resolved,” he says.

“Teachers should be teaching. Taxpayers should expect their money to go towards education and not to labor organizing.”