It said North Korea was also using complicated financial counter-measures and techniques "pioneered by drug-trafficking organisations" that made tracking the isolated state's purchase of prohibited goods more difficult.
The report, compiled by eight UN experts, is part of an annual account of North Korea's compliance with UN sanctions imposed in response to Pyongyang's banned nuclear weapons and missile programmes. The panel reports to the UN Security Council.
A summary of the 127-page report said: "From the incidents analysed in the period under review, the panel has found North Korea makes increasing use of multiple and tiered circumvention techniques."
China, North Korea's main trading partner and diplomatic ally, appeared to have complied with most of the panel's requests for information.