Two human rights watchdogs have called on the government to investigate the disappearance of human rights lawyer Dong Samuel and opposition figure Aggrey Idri and release or charge them.

The two men went missing from the streets of Nairobi, Kenya on January 23 and 24, 2017, respectively.

On January 27, 2017, a Kenyan court ruled against their deportation to South Sudan.

The Human Rights Watch and Amnesty International said credible sources told them that they had seen Dong Samuel and Aggrey Idri in the National Security Service detention in Juba on January 25 and 26.

The men were then removed from the facility on January 27 to an unknown location.

The rights watchdogs say their disappearance is widely viewed as the result of collusion between South Sudan and Kenya, but both governments have denied having custody of the men, or knowledge of their whereabouts.

“Aggrey Idri and Dong Samuel are not with us here. These people disappeared in Kenya. It is not the government of South Sudan that is responsible for their security in Kenya,” said Michael Makuei, the Minister of Information.

In December last year, South Sudanese leaders agreed to release “any person who has been deprived of his or her liberty for reasons related to the conflict” as part of the Cessation of Hostilities agreement.

While the government had released around 30 political detainees in August 2017, both Amnesty International and Human Rights Watch say they believe that many more remain in detention without charge, most of them accused of communicating with, or mobilizing people on behalf of the opposition.

“We have no political detainees to be released. The people who are in our custody are criminals. These are people who are charged of criminal offenses,” Mr Makuei said in response.

The rights groups say disappearance of Dong Samuel and Aggrey Idri are part of a larger pattern by the government to silence its critics by harassing, intimidating, arbitrarily detaining, and forcibly disappearing them.

In many cases, they say people are held for long periods without charge or access to family or lawyers, and have been subjected to torture and other ill-treatment.

They added that these abuses have reached across South Sudan’s borders with human rights activists and opposition members living in Uganda and Kenya reporting intimidation and threats, allegedly from government agents.

“Does it mean that any South Sudanese who disappears in this world, the government is held responsible for his disappearance or what is it?” Mr Makuei questioned.

“These are hasty and unconfirmed reports which are usually written. They are not substantiated and they have no even authority to report. But they are acting on assumption.”

Amnesty International and Human Right Watch also say delays in peace talks should not excuse ongoing detentions and inaction on enforced disappearances.

The talks, which were postponed from last month will start on the 17th May.