A woman who was returning home after having a face-lift in South Korea left immigration officials at Shanghai Pudong International Airport scratching their heads on Monday as they struggled to match the man-made beauty before them with the picture in her passport.

A policeman surnamed Liu stopped the woman because of the obvious difference in her appearance. "Is this really your passport? The woman in the photo is square-faced, but your face is oval-shaped," he said.

The woman told Liu that she had traveled to South Korea for a surgical procedure to have her chin built up and her jaw-line reshaped.

Liu then telephoned the woman's employer and asked her boss to send him copies of the photos appearing in the woman's work permit. As expected, the squared-face woman in those pictures bore little resemblance to the woman in the immigration queue.

Liu and his colleagues then contacted the woman's family. After chatting with members of the woman's family, the police finally accepted that the woman was who she said she was.

"This sort of thing happened approximately 10 times in the past year," Fan Hongxiang, a police officer who works at the airport, told China Daily.

Fan recalled that on April 26, 2006, police struggled to identify a Japanese tourist who had lost 35 kilograms and looked nothing like the photo in his passport. After some investigative work, they eventually verified the man's identity.

Fan urged Shanghai residents who had undergone plastic surgery or whose facial features had changed significantly to provide police with current photographs to avoid confusion in places like immigration queues.

Insiders have said that it is trendy for young women to fly to South Korea for plastic surgery.