Myanmar has begun secretly acquiring key components for a nuclear weapons program, including specialized equipment used to make uranium metal for nuclear bombs, according to a report that cites documents and photos from a Myanmar army officer who recently fled the country.

The smuggled evidence shows Myanmar’s military rulers taking concrete steps toward obtaining atomic weapons, according to an analysis co-written by an independent nuclear expert. But it also points to enormous gaps in Myanmar technical know-how.

The analysis, commissioned by the dissident group Democratic Voice of Burma, concludes with “high confidence” that Myanmar is seeking nuclear technology, and adds: “This technology is only for nuclear weapons and not for civilian use or nuclear power.”

“The intent is clear, and that is a very disturbing matter for international agreements,” said the report, co-authored by Robert Kelley, a retired senior U.N. nuclear inspector. Officials for the dissident group provided copies of the analysis to the broadcaster al-Jazeera, The Washington Post and a few other news outlets.

Hours before the report’s release, Sen. James Webb, D-Va., announced that he was canceling a trip to Myanmar to await the details.

There have been numerous allegations in the past about secret nuclear activity by Myanmar’s military rulers, accounts based largely on ambiguous satellite images and uncorroborated stories by defectors. But the new analysis is based on documents and hundreds of photos smuggled out of the country by Sai Thein Win, a Myanmar major.

The trove of insider material was reviewed by Kelley, a U.S. citizen who served at two of the Energy Department’s nuclear laboratories before becoming a senior inspector for the International Atomic Energy Agency. Kelley co-wrote the opposition group’s report with Democratic Voice of Burma researcher Ali Fowle.

Among the images provided by the major are technical drawings of a device known as a bomb-reduction vessel, which is chiefly used in the making of uranium metal for fuel rods and nuclear-weapons components. The report notes that the Myanmar scientists appear to be struggling to master the technology and that some processes, such as laser enrichment, likely far exceed the capabilities of the impoverished, isolated country.