"(Poland will) work out measures to block the North Korean regime from raking in profits from the illicit rental business by using its embassy buildings jointly with other EU nations, which are in the same situation with us," a Polish Foreign Ministry spokesman was cited as saying by Radio Free Asia.

The North Korean mission, located in the center of Warsaw, is currently leasing out part of its land to a local business, according to the broadcaster.

"Such acts are in violation of the 1961 Vienna Convention on Diplomatic Relations, as well as Polish law," the spokesman said.

The Polish government has sent to the embassy a letter urging it to stop the business while reminding it of UN Resolution 2321, which bans the commercial use of North Korea's overseas mission buildings.

The cash-strapped North is reportedly doing the illegal leasing business in Germany, Romania and Bulgaria as well. (Yonhap)