Zhai Tianlin. (Photo/The Beijing News)

In a public apology on Thursday, actor Zhai Tianlin, who had been hit by plagiarism accusations over his doctoral research papers, said, "I lost myself amid a mentality of vanity and good luck."

Education authorities in Beijing have launched an investigation into Zhai, who has been the target of plagiarism allegations online.

The Beijing Education Commission and the Education Work Committee of the Beijing Committee of the Communist Party of China sent an investigative team to the Beijing Film Academy－where Zhai got his PhD－to look into the matter, the academy said on Thursday.

Zhai, 32, is also a postdoctoral candidate at Peking University. He found himself in hot water last week on social media after a netizen accused him of plagiarism.

The academy launched its own investigation on Monday. It completed its preliminary collection of evidence and notified Zhai, it said, adding that it has zero tolerance for academic misconduct and will look into other matters uncovered by netizens.

"After I starred in a few films and TV series, I became full of myself and forgot that honesty is the most important principle," Zhai said in his apology letter posted on Sina Weibo on Thursday.

"Vanity misled me, and I brought this attitude into writing academic papers. I will withdraw from postdoctoral research at Peking University and I am deeply sorry to my school, teachers, fans and the public," he wrote.

Zhai raised a flurry of chatter online in August when he said in a live video appearance he did not know what the China National Knowledge Infrastructure was. CNKI is the largest and most widely used online academic library in China for university students writing theses and dissertations.

A post by a Sina Weibo blogger claimed one of Zhai's papers, which was published in an academic journal, was uploaded to CNKI and the 2,783-word article showed a 40.4 percent similarity with other people's work.

Another post by the same netizen claimed Zhai's doctoral dissertation could not be found in the CNKI database, while all the graduation dissertations written by his classmates were there.

Zhai's studio said on Feb 8 that he obtained a PhD from the Beijing Film Academy in June, and all his academic papers and dissertation were written by him under the guidance of supervisors.

He had met all graduation requirements from the academy and was willing to be held accountable for any academic misconduct, the studio said.

Netizens later said that Zhai's supervisor, Chen Yi, former director of the academy's performance institute, has only a bachelor's degree and has not published any academic papers. Doctoral supervisors at the academy are supposed to have a doctorate themselves and should have published at least eight academic papers and two academic monographs in the past five years.

Peking University notified Zhai in person of the results of its preliminary investigation on Wednesday, the school said on Thursday.

The university is aware of Zhai's desire to withdraw from the postdoctoral program and will act appropriately, it said.