Russian authorities have imposed a ban on imports of dairy products into the country from six Ukrainian factories.

Trade relations between the two countries were deteriorating since Russia annexed Crimea last month.

The Russian consumer rights watchdog Rospotrebnadzor said that it found that the products violated dairy regulations after conducting laboratory tests.

"To ensure consumer rights Rospotrebnadzor has suspended imports into the Russian Federation of (six) Ukrainian dairy producers," the agency stated.

A source from Rospotrebnadzor was quoted by Interfax as saying, "The information was conveyed consistent with the WTO regulations to the authorized body, the Federal Customs Service and the department of Rospotrebnadzor [the Federal Service for Supervision of Consumer Rights Protection and Human Well-Being] in Russian constituent territories."