Led by the U.S. based the self-exiled Turkish scholar Fethullah Gulen, the schools have drawn concern not only for the quality of educational and curriculum, but there is growing concern that the movement and investigation has left a negative impression on Turks in the U.S. and on the image of Turkey.
The FBI launched an investigation last June into foundations and schools connected to the Gulen movement in the states of Ohio, Indiana and Illinois, for lack of transparency in financial and legal records.
The probe was launched after Mary Addi, a teacher at one of the Ohio schools, alleged fraud in the group’s records.
Gulen recruits foreign teachers and then takes a cut of their salary, Addi told national television news magazine “60 Minutes.”
She said she learned about the alleged scheme after she married a Turkish teacher. After her husband was paid, he would cash his check and return 40 percent of his earnings to the school for "a secret fund" used by the movement.
Addi’s allegations have forced the U.S. government to investigate immigration fraud as well as misuse of taxpayer money related to the movement.
It has also caused many to wonder about the actual intent of the schools.
Gulen schools are the largest charter network in the U.S., with 146 schools in 26 states, and the majority of the teachers are Turkish. The schools receive approximately $150 million annually in taxpayer money.
But most of the contracts for construction and operations have gone to Turkish businesses, an issue that has raised red flags for the U.S. government.
Former member of the Ohio State Board of Education and Dayton Board of Education Chairman, Jeffrey J. Mims, complained about the lack of transparency in operations at the Gulen-linked Horizon schools in Ohio.
"We are concerned about these schools," said Mims, while noting that these schools leave a negative impression on Turkish community in the U.S.
He said that Gulen schools are teaching outside of mainstream educational principles. “All students in our community are important for us. We cannot tolerate an educational facility teaching something out of the mainstream educational principles."
Although he did not go in detail about the curriculum set by Gulen schools, several former teachers shared their experiences as evidence of an improper curriculum and poor educational quality.
Richard Storrick, a former Ohio math teacher, said discipline was biased and it favored certain teachers and students.
“A Turkish student missed more than a month of school and paid no consequences,” he said. "Likewise, administrators did nothing about complaints that a Turkish teacher called African-American students ‘monkeys’ and ‘dogs’ and promoted another known for sleeping in the classroom,” said Storrick, who spoke to CBS News.
Mims said it is intolerable that students are called by such names and are trained with "a false educating method" which has the potential to lead to future failure.
"No teacher in the building had any kind of curricular support. The principal told us to look online for copies of the state standards that were in effect at the time and then print copies for classroom decorations," said Matt Blair who shared his experience at an Ohio school on an online blog.
"Teachers had no textbooks and no reference material, not even classroom sets of books. I bought my own textbooks and then cut-and-pasted copies for students," he added, noting that student grades were mostly biased in order to please parents.
The Gulen movement has opposed the Turkish government since 2013 and is accused by Turkey of constructing a "parallel state" within Turkey by setting up its cadres in public offices.
Turkey has requested that the U.S. extradite Gulen, but there has been no official response from the U.S.
The federal investigation, however, is beginning to cause a backlash for certain communities.
Adil Baguirov, a member of the Dayton Public Schools Board of Directors told The Anadolu Agency that the investigation into the schools has caused a negative impression on not only Turkish schools, but the Muslim community, too.
The allegations have caused many to view other charter schools, particularly those operated by Turkish and Muslims, as biased, he said.
"Horizon schools left a negative impression not only on Turks but also Muslims living and doing business here," Baguirov said. "These schools are called Turkish Islamic schools in American media. We try to do our best to get rid of the impression they left."
Members of the Meskhetian Turks, a Turkic tribe with a significant population in Dayton, Ohio, is concerned.
Community Center Chairman Islam Shahbenderov said that the Gulen schools across the U.S. have significant problems and have left a bad impression on Turkey.
"All these are very upsetting because we are also accounted for the wrong things they did," Shahbenderov said. "What is more, the people linked to the movement go to the U.S. Congress and other institutions to criticize the elected government of Turkey. They behave as if they have declared war on the Turkish state."
The Ohio Board of Education has launched its own probe of the nearly 20 Gulen-linked charter schools in the state.
The Chairman of the New-York based Her Sey Turkiye Icin, or All for Turkey, believe the backlash against Turks is due to the negative propaganda about the schools.
"These repercussion cause problem between Turkish and American communities particularly, the Meskhetian Turks,” said Murat Berk.
The Gulen movement styles itself as a moderate Islamic community that mainly bases its missionary facilities on education.
Although the public face of the movement is colored by educational and cultural activities such as the Turkish Olympics, those who have broken ties with Gulen and are familiar with the inner workings of the community, tell a different story. They characterize the movement as an ultraconservative secret society.
“We need to resolve this,” said Berk. “There are serious accusations against the charter schools and we do our best not to attribute these to the whole Turkish community in the U.S.,” he added.