Former US presidential envoy Princeton Lyman on Thursday called for an end to illegal restrictions on the media in South Sudan, citing the closure of the office of Free Voice, a partner of the US Institute of Peace.

Lyman was one of several witnesses at a US Senate Foreign Relations Committee hearing in Washington on Thursday, which was called by lawmakers to discuss the current situation in South Sudan.

He told the committee, “The US should defend strongly a free media – something the Government of South Sudan has drastically curtailed over the past three years. Since as early as 2012, journalists in South Sudan have been harassed, beaten and in some cases assassinated.”

“As one recent example, Free Voice, a peace programming group partnered with the US Institute of Peace, was shut down despite it having no partisan leanings. A leading newspaper was shut down at the same time. These practices must be stopped and the perpetrators punished,” Lyman said.

The former US official was referring to an incident in August when armed men claiming to represent the National Security Service entered the Free Voice premises in Juba and put a lock on the door. They did not present any warrant or judicial order authorizing them to seize the property.

In additional remarks to the Senate committee, Lyman stressed the key role of media in the survival of peace: “With limited other outlets for expression of opinion and accountability, a free media is an essential adjunct to this peace agreement.”

He further urged the lawmakers to support civil society and women’s participation in the peace process saying, “The US should provide financial and political support for civil society, women’s groups and individuals, for the professionals assigned to constitution drafting committees and judicial reform, and for economic reform institutions, reconciliation processes, and other aspects of participation of non-belligerents in the transformation process.”

Lyman was first appointed to the State Department’s Sudan and South Sudan office in 2010 and was promoted by President Barack Obama as his special envoy in March 2011, a position he held until December 2012.

He now serves as a senior advisor to the president of the US Institute of Peace, an organization created and funded by the US Congress.