Humour is very much a personal thing. For the two Vietnamese students inspired by the film character Borat, who dressed up in skimpy "male bikinis" and tugged fake pubic hair from each other's bodies, nothing could have been funnier.

But officials deemed the performance at a college event utterly inappropriate and the pair were promptly expelled for a year. Not surprisingly, the incident and the subsequent fallout have been seized on in the communist nation's usually staid and scripted media as well as the blogosphere. "I cannot understand how they could do such an anti-cultural thing," said Nguyen Dinh Van, a letter writer from Hanoi. "I cannot accept it."

The two students donned the swimwear, made famous by the British actor Sacha Baron Cohen's spoof character in the 2006 film Borat: Cultural Learnings of America for Make Benefit Glorious Nation of Kazakhstan, to perform at the 20th anniversary party for Hanoi's FPT University.

The film, featuring Borat as a supposed Kazakh journalist visiting the United States, was accused of being racist, homophobic and anti-Semitic. Kazakhstan's government also complained that it portrayed the country unfairly. Such controversy provided much-welcomed free publicity for the film, parts of which feature Borat wearing the so-called "mankini" – a cross between a thong and swimming trunks for men. According to a report in Thanh Nien, a publication of the Vietnam National Youth Federation: "Many members of the 4,000-strong audience clapped their hands and cheered the nearly naked students on, although some female audience members voiced their disapproval." Video clips of the incident were posted on the internet but then taken down. But images available on blogs suggest that the two students danced, wrestled and then pulled fake pubic hair from each other.

Nguyen Thu Nga, head of the communications department at FPT, a company whose business interests include telecommunications, said the performance was an accident. She told reporters that the dance was not included in the show's plan and was a spur-of-the-moment action by the students. One member of the show's organising committee said: "It was like walking through a door and being slapped."

In addition to their reported suspension, the Hanoi Cultural Inspectorate also fined the college 4 million dong (£135) for offences including the "use of improper clothing".