Thousands of tons of timber from Myanmar have continued to be imported into the U.S., despite government sanctions against the country’s state-run timber company, a new report from a watchdog environmental advocacy group has revealed.

The Guardian reports that, according to the U.K.-based Environmental Investigation Agency (EIA), over 3,000 tons of timber from Myanmar have been imported into the U.S. over the last two years.

Teak, prized for its natural water resistance in the building of luxury yachts, furniture and flooring, has been a controversial material for years because of deforestation in Myanmar.

U.S. federal law, under the Lacey Act, requires that imports of wildlife, fish or plants must be legally harvested under the exporting country’s laws. In 2014, a Myanmar law was passed under the former government that banned exports of raw timber – though it allowed exports of milled timber – to curb deforestation. But the EIA has warned the military-controlled government is likely not following the law, and the country is on track to lose its forests by 2035.

The report names the top 12 U.S.-based companies that have imported teak from Myanmar since the start of the coup. Two companies, East Teak Fine Hardwoods and J Gibson McIlvain, have what the group says is a duopoly on Myanmar teak imports in the U.S., making up 88% of all teak imports over the past two years with more than 1,600 tons of imports combined.