The University of Calgary has launched an investigation into the retraction of a study from 2000 in which researchers in Canada and South Korea said they used gene therapy to reverse Type 1 diabetes in mice.

"As a research-intensive university, we strive to uphold the integrity of our research," spokesperson Colleen Turner said in an email Thursday.

"We have measures in place to maintain the utmost standards of academic rigour in our research. This is an anomaly and we take the retraction seriously. We are currently looking into the matter."

Thursday's issue of the journal Nature contains the retraction by lead author Hyun Chul Lee of Yonsei University in Seoul, South Korea, and two other researchers: Kyung-Sup Kim of South Korea and the University of Calgary; and Hang-Ceol Shin of South Korea.

The three researchers said they sought the retraction because they could not reproduce the results of the gene therapy experiment.

Fellow study author Ji-Won Yoon of the University of Calgary is deceased. The final researcher, Su-Jin Kim, maintains the results are still valid and did not sign the retraction, the journal said.

In 2000, the researchers said they used gene therapy to regulate blood sugar levels in rodents, and that the treatment lasted for five months.