Not classified but marked “for official use only,” the DHS analysis states that, while downplaying the severity of the coronavirus, China increased imports and decreased exports of medical supplies. It attempted to cover up doing so by “denying there were export restrictions and obfuscating and delaying provision of its trade data,” the analysis states.

The report also says China held off informing the World Health Organization that the coronavirus “was a contagion” for much of January so it could order medical supplies from abroad — and that its imports of face masks and surgical gowns and gloves increased sharply.

Those conclusions are based on the 95% probability that China’s changes in imports and export behavior were not within normal range, according to the report.