A school linked to Fetullah Terrorist Organization (FETO) in the state of California is under investigation, accusing its former principal Hayri Hatipoglu of defrauding the school.

According to the local newspaper East Bay Express, Hatipoglu, who was principal of the BayTech school in Oakland's Bay Aream suddenly resigned from his post along with four senior staff members and two out of the five board members of the school.

Disappearing following his resignation, Hatipoglu reportedly left for Australia with his family.

The Oakland Unified School District (OUSD) launched an investigation, while the school’s three remaining board members started their own investigation hiring a third party.

The board members accuse Hatipoglu of covertly changing his contract so he would receive a severance of $450,000 for three years.

‘Plenty of evidence’

In an interview with the East Bay Express, board member Fatih Dagdelen said, “According to his contract, he'd get paid a six-months salary if he resigned, but all of a sudden his contract said he'd get paid two-and-a-half years further.”

Dagdelen added, “We have a lot of evidence and believe there's a fraud.”

Dagdelen refused to say why Hatipoglu had resigned but there had been a fallout between Hatipoglu and the Turkish directors of the school after he resigned.

The story said that OUSD received many complaints over the last decades to investigate the school’s ties with FETO, but were dismissed by the BayTech administration, “calling any attempts to question the school's ties to Fethalluh Gulen's followers a form of discrimination.”

'OUSD takes seriously allegations of financial mismanagement'

Joshua Hendrick, a professor at Loyola University Maryland, said many followers of FETO deny links to the organization, namely those who organize charter schools in the U.S.

The district’s spokesperson John Sasaki confirmed the investigation launched against the school and said financial mismanagement allegations in their schools are being taken seriously.

“As the charter authorizer, we have been informed of allegations of financial impropriety at BayTech,” Sasaki said.

The BayTech charter school was opened in 2003, run by non-profit Willow Education foundation, which was founded by Suleyman Bahceci -- founder of another FETO-linked schools in Texas, Utah and southern California.

The East Bay Express said Bahceci and other staff and board members of BayTech “have obvious ties” to FETO.

Anadolu Agency has attempted get comments from school officials but has so far failed to make contact.

Residing in Pennsylvania since 1999, FETO's ringleader, Fetullah Gulen, is known as the man who controls around 140 charter schools and $500 million annually from the U.S. government, according to some U.S. media reports.

While the administrators of FETO schools denounce they are connected to FETO's leader Gulen, the financial relationships between the schools and other FETO institutions confirm the relationship.

FETO's schools nationwide are part of the largest charter schools network in the U.S. Some of the schools are currently under FBI investigation for irregularities, unlawful profits, corruption, fraud and forgery.

Turkey has accused the FETO and Gulen of being the masterminds of the defeated July 15, 2016 coup, which martyred 251 people and left some 2,200 injured.

They are also accused of infiltrating educational and other institutions in Turkey and worldwide for nefarious means, including subverting the state.