An Interior Department scientist returned to work Friday, six weeks after he was suspended in connection with a probe of whether he improperly assisted another polar bear researcher in obtaining a federal contract.

The decision to suspend federal wildlife biologist Charles Monnett last month sparked a public debate about whether he was being penalized because he had authored a paper in which he said he observed drowned polar bears, an image that helped crystalize the possible dangers associated with global warming.

Although Monnett was questioned about the 2006 paper on polar bears, Interior’s Office of Inspector General said in a letter last week that Monnett was being investigated for improperly helping a researcher at Canada’s University of Alberta draft a response to a federal request for proposals on a polar bear study. Monnett chaired the committee that eventually awarded the contract to the university.

In the letter, the special agent in charge quotes the contract officer as saying that if Monnett had informed her about his collaboration with the University of Alberta researcher, “she would have warned you that such actions would have been highly inappropriate under procurement integrity policies and procedures.”

Bureau of Ocean Energy Management, Regulation and Enforcement spokeswoman Melissa Schwartz wrote in an e-mail that Monnett “was informed that he will have no role in developing or managing contracts of any kind, and will instead be in our environmental assessment division.” She added, “The return of an employee to work does not suggest that future administrative actions cannot/will not be taken.”

Public Employees for Environmental Responsibility (PEER), the group that is representing Monnett, said the fact that he is back on the job shows that the bureau’s director, Michael Bromwich, erred in blocking the scientist from conducting his work. Jeff Ruch, the group’s executive director, said the probe of the wildlife biologist amounts to “a fishing expedition” and that he was targeted because of his work on climate change.

Schwartz said that the IG probe of Monnett is ongoing, adding, “There is no truth to any suggestion that the return to work is in any way tied to PEER’s allegations against bureau leadership.”