Turkey has summoned Sweden's ambassador to the foreign ministry after Stockholm accused Ankara over a court ruling which it claimed legalised sex with underage children, the Turkish foreign minister said on Monday.

"It is a scandal for a foreign minister to post such a tweet based on false news or speculation," Foreign Minister Mevlut Cavusoglu said in televised comments, adding that the Swedish envoy was summoned to his ministry.

Swedish Foreign Minister Margot Wallstrom had tweeted on her official account that the "Turkish decision to allow sex with children under 15 must be reversed", following a controversial ruling by the Turkish constitutional court.