Flamboyant Peking University president Zhou Qifeng has sparked a public debate over filial piety after returning to his ancestral home in Hunan province for his mother's 90th birthday.

Pictures of the professor kneeling in front of his mother before they locked in an emotional embrace have circulated widely on the internet on the mainland. Some people hailed Zhou as a role model for filial piety while others dismissed the whole episode as a show.

'He is a true role model because filial piety is at the top of the 100 benevolent virtues,' one person said in a comment posted on the Web.

'A birthday celebration is rather a private matter; why should he make it so high-profile?' asked Jin Manlou , a Shanghai-based writer.

Zhou, 65, has been no stranger to controversy since becoming the university president in November 2008. He led a large university delegation to Chongqing in November last year to pay tribute to 'creative reforms' launched by Bo Xilai , the municipality's now- disgraced former party secretary.

He has also helped shield controversial Professor Kong Qingdong from fallout over comments he made during an internet television talk show in January, when he called Hong Kong people 'running dogs of the British government'.

Zhou, who studied at the University of Massachusetts, also caused a stir for calling the US education system 'a mess' in a public speech.

During his visit home, a large crowd had gathered at his home and a small camera crew was present. His mother was reported to have recounted the hardship Zhou suffered at school, coming from an impoverished family in Liuyang.

Zhu knelt for 10 minutes before his mother, telling her: 'I'm sorry for not be being able to come back for your 80th birthday because I was busy at work.' They then broke into tears and hugged.

An official from Peking University's publicity department said the school was not in a position to comment on Zhu's visit as it was a private matter.

However, a signed commentary in the Global Times said both Zhou and Peking University should explain to the public whether he was aware of the cameras beforehand.

Editor-in-chief Hu Xijin wrote on his microblog on Sunday that while it was right for a prominent person such as the president of Peking University to set an example on filial piety, the virtue should not be turned into a public display.

'If he knowingly co-operated with the media on this occasion, I'd feel ashamed for him,' Hu added.