Fulton Science Academy High School in Alpharetta could lose its public school charter and be forced to close at the end of the school year, in part, for illegally making students pay for mandatory classes.

Robert Avossa, superintendent of Fulton County Schools, plans to ask the school board Tuesday to begin the process of revoking the school’s charter on multiple grounds, including charging seniors $500 and requiring them to go online for classes needed for graduation.

If approved, the closing would be effective in June.

Officials with the high school did not return calls seeking comment. They will be entitled to a hearing.

The academy’s sister middle school lost its charter, closed and reopened as a private school earlier this year based on some of the same complaints about management, record-keeping and transparency now facing the high school. This includes a decision by the leadership of both schools and a sister elementary school last year to take out — and then quickly default on — an $18.9 million construction loan.

Kenneth Zeff, the school system’s new chief strategy and innovation officer, said public schools may have latitude to charge students for some elective courses, but not for classes required for graduation.

“That violates the integrity of public education,” Zeff said. “It has a chilling affect on who attends your school.”.

He said the charter high school’s decision to charge students for classes is likely due to the school’s larger problem of being unable to connect to the community.

The school, which auditors found had some connections to supporters of Fethullah Gulen, a prominent Turkish imam, has been unable in seven years to reach the enrollment goal of 350 promised in its charter application to Fulton County Schools, Zeff said.

“It stems from the fact there’s no outcry from the community, no support for this school,” he said.

The school now has 250 students, a very small enrollment for a high school, and has “cut too many corners,” Zeff said.

He met with members of the school’s board Monday to discuss Avossa’s planned recommendation to the board.

Avossa said the school system is committed to helping students who want to transition into other county schools immediately or, if the school board approves, after the academy closes as a public school.