Gov. Kate Brown strongly defended Oregon's marijuana regulations in a letter Tuesday to U.S. Attorney General Jeff Sessions and publicly discredited an Oregon State Police analysis that concluded the state remains a top black market source for the drug.

Brown detailed the steps Oregon has taken to tackle illicit trafficking and criticized the analysis, which Sessions cited at length in a letter to the governor last month.

Brown wrote that the report was based on information collected before the state began regulating recreational marijuana and doesn't reflect the "on the ground reality in Oregon in 2017."

She noted that state police Superintendent Travis Hampton shared her concerns and she released a letter that Hampton wrote earlier this month to Sessions distancing his agency from its own report.

"The Oregon State Police determined that the draft report required significant additional work and revision because the data was inaccurate and heavily extrapolated conclusions were incorrect," Brown wrote.

The Oregonian/OregonLive earlier this year obtained an early draft of the controversial report and published a story that quickly drew the attention of top federal law enforcement officials who expressed dismay by its findings.

The draft report concluded that Oregon has an "expansive geographic footprint" on the black market, with a half-dozen counties leading the way in supplying much of what is shipped out of state. The report's other key takeaways: Overall marijuana production in Oregon far outpaces demand, hash oil manufacturing has fueled a rise in explosions and serious injuries and the state doesn't comply with key federal marijuana enforcement priorities.

State police, who received federal money for an analyst to collect and examine marijuana data, denounced the draft when it learned the news organization had obtained a copy of it.

Hampton also said in his letter that the document was "the first and least defensible draft" and that it was "not accurate, not validated and outdated."

"Unfortunately," Hampton wrote to Sessions, "you sourced the same leaked draft as evidence against Oregon's marijuana regulatory structure."

The governor and Hampton are making their case as Oregon and other states with legal marijuana programs face scrutiny from a presidential administration that takes a dim view of the drug. While President Barack Obama tolerated legal marijuana, the top federal law enforcement official under President Donald Trump has made clear his opposition, calling cannabis "only slightly less awful than heroin."

Earlier Tuesday, Brown's office issued a statement in response to questions about feedback that the governor's aides gave to state police about the marijuana report.

The governor's office, the statement said, "requested a more thorough analysis" after reviewing a draft of the report earlier this year. That draft, the statement went on to say, revealed a "clear bias" as well as a "blatant disregard of any professional research standards."

The state police produced multiple drafts; it's unclear which one was reviewed by the governor's staff.

"By using incomplete data, inaccurate research and unreliable sources, the flawed document drew unsubstantiated conclusions about cannabis legalization in Oregon to serve the author's personal agenda," Brown's office said.

Ravi Channell, the analyst who helped draft the report, works for the Oregon-Idaho High Intensity Drug Trafficking Area, a federal agency that focuses on drug enforcement.

Channell spent months on the analysis, but it wasn't until early this year that state police brass read it, Capt. Bill Fugate said Tuesday.

The document was tinged with opinion and "suggestive words" and cited publications such as High Times, a magazine about marijuana culture, as sources, Fugate said. It also cited the World Bank, the U.S. Department of Justice and the Association of Oregon Counties.

"As an agency, our job is to be objective and to present information that will be used by healthcare workers, public safety and policy makers," Fugate said. "Our job is not to have an opinion."

Internal state police emails obtained by The Oregonian/Oregonlive show supervisors in the agency's drug enforcement section communicated about the report and planned to have it completed in time to brief lawmakers before this year's legislative session.

Channell even gave a national presentation last fall about the report along with other drug enforcement data analysts from states with legal marijuana policies. He discussed at length the methodology for the analysis, how the agency planned to use the federal government's enforcement priorities as a "framework" and how the report would examine crimes, as well as public health trends associated with cannabis.

Channell told the audience that he hoped the report, once public, would inform policymakers, law enforcement and "even the pro-marijuana camp."

"We know at the end of the day we want an objective and empirically based piece of research," he said, according to a video of his speech, which was uploaded to YouTube by the Santa Clara County District Attorney's Office.

But those efforts stalled out last spring.

Shortly after a meeting between top state police officials and Jeff Rhoades, the governor's marijuana policy adviser, Channell emailed Sgt. Tyler Bechtel. Bechtel, a drug enforcement supervisor, also had a hand in the report.

"Sorry but I have run into a morass of confusion," Channell wrote. "I need refined instructions as to what needs to happen to this report."

He went on to say he tried to revise the document but worried that the result had become a "disjointed" effort.

He also doubted his ability to make additional changes, saying: "I cannot rebuild a year of work in such a short period of time."

Included in the email: a chart depicting an ascending line representing the report's progress between April 1, 2016, and March 2017 and then a steep drop in March, after the meeting with the governor's aide, Rhoades.

It was unclear what revisions he was asked to make. Channell didn't respond to text messages from The Oregonian/OregonLive this week.

State police officials knew the report was politically sensitive, said Seth Crawford, an economist by training and a hemp producer whose extensive analysis regarding the value of the state's cannabis crop was published in an academic journal in 2013.

State police asked Crawford to look at some of their work for the analysis. But first they wanted him to sign a non-disclosure agreement.

In January, Lt. Gregg Withers, who is assigned to the drug enforcement section, emailed Capt. Jon Harrington, requesting a "quick turnaround" on drafting a non-disclosure agreement for Crawford since the state police planned to present the analysis to legislators "during the early stages of the legislative session."

Said Crawford: "They were afraid if any of the information got out, it could be politically sensitive and it could undermine the report before it was released officially."

-- Noelle Crombie

503-276-7184; @noellecrombie