Stem cell pioneer Hwang Woo-suk says he will speak "at the appropriate time" on the controversy over how his team obtained human eggs for experiments.

Before entering a CNN media conference in Seoul Monday, the Seoul National University professor told reporters that all he knows is that American researcher Gerald Schatten ended their partnership, and that he will tell more later.

SNU professor Ahn Gyu-ri, Hwang's research partner who accompanied him to the event, said they are trying to confirm the facts and will tell all after reviewing Schatten's remarks.

Both avoided direct comment on the controversy and declined to say when they will issue a statement.

Schatten on Sunday dropped a bombshell by saying he will no longer work with Hwang, citing ethical violations in how the team used human eggs from its own female staff.

The Science and Technology Ministry on Monday said it will look into the controversy.