UN human rights special rapporteur Clement Nyaletsossi Voule arrived in Zimbabwe on Tuesday as the country’s poor human rights record returned to the spotlight.

Voule arrived in Harare two days after a doctor who led a strike for higher wages and better working conditions was allegedly abducted by state agents.

Rights groups say that since January more than 50 trade union leaders and opposition activists suspected of planning antigovernment protests have also been abducted and tortured.

Union leader and activist Peter Magombeyi, the president of the Zimbabwe Hospital Doctors Association, disappeared on Saturday night.

His colleagues allege Magombeyi was abducted by security forces in an attempt stop the strike, which has interrupted healthcare services in hospitals.

Voule’s visit to Harare also follows a government clampdown on antigovernment protests including a countrywide ban on demonstrations by the opposition MDC.

Voule said the visit to the country was to learn first-hand about Zimbabwe’s policies on rights to peaceful assembly.

 “My mission will also serve to identify the opportunities and challenges the government faces in implementing articles 21 and 22 of the International Covenant on Civil and Political Rights, particularly in relation to the management of assemblies in the context of the recent protests.”

On Tuesday, Zimbabwe’s government denied involvement in Magombeyi’s alleged kidnapping, saying they had instructed police to investigate the matter.

Speaking at a post cabinet briefing, acting information minister Kazembe Kazembe said: “Government is particularly concerned over the growing trend of incidents of this nature, which put the lives of the country’s citizens at risk, while at the same time appearing to be calculated to tarnish the image of the country.”

In 2015, Itai Dzamara, an outspoken critic of then president Robert Mugabe, was allegedly abducted by suspected state agents and has not been seen since.