Cloning pioneer Hwang Woo-suk’s research team has vowed to step up its experiments despite the recent ethics controversy surrounding the source of human eggs used in the team's studies.

The researchers said Friday that they felt obliged to actively continue their work given the Korean public’s high expectations for stem cell research.

Meanwhile, bioethics experts stressed the need to firmly establish an institutional mechanism that would enable stem cell research to be conducted in a transparent and smooth manner, citing the growing international competition in the field of embryonic stem cell research.

The team’s comments come one day after Hwang admitted in a news conference that his team last year used ova donated by two of its researchers.

Hwang added that he would resign from all of his official posts, including president of the World Stem Cell Hub, and focus on his research.