An investigative committee of Seoul National University on Sunday questioned the research team of cloning pioneer Hwang Woo-suk.

At the university's School of Veterinary Medicine, committee members grilled professors Hwang and Lee Byung-chun and 20 other researchers on stem cell research.

A grim-faced Hwang, who had not shown up at his home or lab after his Friday news conference, appeared for questioning at his lab at 10:30 a.m.

He shunned reporters' questions on his way to the room.

The panel moved up its interrogation of Hwang from next week in the wake of revelations on Hwang's research.