The U.S. journal Science will retract a paper by cloning pioneer Hwang Woo-suk published earlier this year as requested by Hwang and his former colleague Gerald Schatten.

In a news conference Friday, Science chief editor Donald Kennedy said he will see how the probe on the paper goes and then decide whether to investigate another of Hwang's theses published by the magazine in February last year.

He said he is unaware of academic misconduct in Hwang's paper.