(AP) -- The government's suspension of an Arctic scientist was related to how a polar bear research project was awarded and managed and not his earlier scientific work detailing drowned polar bears, a watchdog group said Monday.

Charles Monnett, a U.S. Bureau of Ocean Energy Management, Enforcement and Regulation biologist, was placed on administrative leave July 18, pending final results of an inspector general's investigation into "integrity issues."

The advocacy group Public Employees for Environmental Responsibility said he was never told why he was suspended or what the focus of the investigation was.

However, Monnett received a letter dated July 29 from Special Agent Eric May in the Department of the Interior's inspector general's office, outlining the focus of the investigation, which is related to the study being conducted jointly with a Canadian university. He asked Monnett to be prepared to answer further questions in an Aug. 9 interview.

"We intend to discuss actions taken in your official capacity as a biologist and any collateral duties involving contracts as an official of the U.S. Government," May wrote in the letter, a copy of which was provided by the . "Those actions include the procurement of a sole source, cost-reimbursable contract with the University of Alberta to conduct a study titled `Populations and Sources of the Recruitment in Polar Bears.'"

Monnett coordinated much of the agency's research on Arctic wildlife and ecology and had duties that included managing about $50 million worth of studies.

A memo dated July 13, sent to Monnett by contracting officer Celeste H. Rueffert, said that information raised by the investigation "causes us to have concerns about your ability to act as the Contracting Officer's Representative in an impartial and objective manner on the subject contract."

A stop-work order was issued that same day for the polar bear tracking study.

"The stop-work order has now been rescinded, and the study is continuing to move forward," ocean energy management bureau spokeswoman Melissa Schwartz said in an email to The Associated Press on Monday.

All scientific contracts previously managed by Monnett are now being handled by other agency scientists.

In his letter, May also told Monnett to be prepared to address specific issues like compliance with the Federal Acquisition Regulations, disclosures of personal relationships and preparation of field work.

The Department of Justice declined criminal prosecution, May wrote, adding next week's interview will be administrative in nature, and results will be forwarded to "the BOEMRE Director for appropriate action."

"There were no mysteries about how Dr. Monnett handled his responsibilities related to the procurement of this or any other research project in his scientific portfolio," PEER Executive Director Jeff Ruch said in prepared statement.

He said their concern is that the inspector general's office "has expanded its vindictive fishing expedition into yet another area beyond its expertise." PEER is seeking the documents the agency used to justify Monnett's suspension.

PEER has claimed officials initially didn't tell Monnett why he was suspended or under investigation. After an Associated Press story on the investigation last week, the agency's director informed Alaska staff that the action was unrelated both to an article that Monnett wrote about presumably drowned Arctic polar bears and to his scientific work.

Michael Bromwich, director of the ocean energy management bureau, told agency staff in Alaska via email Friday that it instead was the result of new information on a separate subject that was recently brought to officials' attention.

Documents provided by the showed questioning by investigators earlier this year focused on the polar bear observations that Monnett and researcher Jeffrey Gleason made in 2004.

Monnett and Gleason were conducting an aerial survey of bowhead whales in 2004 when they saw four dead polar bears floating in the water after a storm. They detailed their observations in an article published two years later in the journal Polar Biology.

In the peer-reviewed article, they said they were reporting, to the best of their knowledge, the first observations of the bears floating dead and presumed drowned while apparently swimming long distances.

They said their observations suggested the bears drowned in rough seas and high winds. They also added that the findings "suggest that drowning-related deaths of may increase in the future if the observed trend of regression of pack ice and/or longer open water periods continues."

The article and presentations helped to galvanize the global warming movement.