The final report has been submitted to the UN Security Council, and is likely to be published later this week.
Singapore’s government said it was aware of the cases and had begun investigating where there was “credible information” of possible offences.
Both the UN and Singapore ban the sale of luxury goods to North Korea.
Global sanctions against North Korea have tightened considerably over the last two years as Pyongyang has continued to conduct nuclear tests and launch missiles.
Despite the recent development that unprecedented talks between North Korea’s leader Kim Jong-un and US President Donald Trump may take place later this year, UN sanctions against North Korea will remain in place.
Analysts say the alleged violations by Singapore companies, if proven, raise questions about how widespread such breaches might be across Asia.
The leaked UN report highlights two Singapore-based firms, among others in Asia.
It alleges the two firms supplied a range of luxury goods to North Korea, including wines and spirits, until as recently as July 2017.
Under UN Sanctions, it has been illegal to sell luxury items to North Koreasince 2006. And Singapore’s laws have banned the sale of these items to North Korea for several years. (Courtesy BBC)