Sweden's housing minister has stepped down amid mounting questions over his contacts with Islamists and ultra-nationalists from his native Turkey.

Mehmet Kaplan, a 44-year-old Green Party member and former spokesman of Sweden's Muslim Council, says Monday he has done nothing wrong but was resigning because the criticism against him was interfering with his ability to perform his job.

Kaplan came under pressure after Swedish media published photos showing him dining with Turkish Swedish leaders, including the local leader of the Gray Wolves, an ultra-nationalist group.

He also faced criticism for having compared Israel's treatment of Palestinians to how the Nazis persecuted Jews.

Kaplan told reporters his resignation was "not a confirmation of reports about me that I consider wrongful. I know who I am and what I have done."