A letter published in this week’s issue of Science has retracted a paper that was flagged last fall by the journal’s editor as possibly not “reliable.”

The three authors of the letter, all scientists at the University of Missouri at Columbia when they co-authored the original paper, were cleared of any misconduct by a university investigation this year.

But the investigation found that a fourth author of the paper, Kaushik Deb, who had been a postdoctoral researcher at Missouri, had intentionally falsified and fabricated digital images in the Science paper. He has resigned from the university, and his co-authors could not locate him to sign the retraction. The Columbia Missourian reported today that he had apparently fled the country.

In the letter of retraction, the three other authors admit that they have not found the raw image files for many of the faked ones, “raising the possibility that the data they represent may also be suspect,” they write. The lead author of the paper and the retraction is R. Michael Roberts, a professor of animal sciences and of biochemistry at Missouri. The other two authors have moved to new positions, at the University of Illinois at Urbana-Champaign and at Seoul National University, respectively.

The paper, published in February 2006, was on the hot research topic of early embryo development. —Lila Guterman