The United Nations human rights office expressed concerns Friday over former Crown Prince Hamzah bin Hussein's whereabouts, saying that it is unclear whether he remains under de facto house arrest.
The global body also said there is a lack of transparency surrounding at least 16 detentions.
"We'd like to state that aside from broad accusations it appears that no charges have been yet brought and we are concerned at the lack of transparency around these arrests and detention," U.N. human rights spokesperson Marta Hurtado told a Geneva news briefing where she was asked about the case, as Reuters reported.
Spokeswoman Marta Hurtado told reporters in Geneva that the rights office was following the situation, which erupted on April 3.
Hurtado said: "We are aware that there is an ongoing investigation but still it's not clear to us if following the mediation on April 5, Prince Hamzah is still under de facto house arrest or not.
"Aside from broad accusations, it appears that no charges have been yet brought and we are concerned at the lack of transparency around these arrests and detentions."
Hurtado said that any investigation, including one on the basis of national security, had to be conducted in line with international human rights law.
The arrests "were the latest in an escalating series of measures over the past year targeting, in particular, criticism of government policies and corruption", she added.
Jordan's King Abdullah II said on Wednesday sedition had been quashed after a rift with his half-brother and former heir Prince Hamzah, whom the government had accused of links to efforts destabilize the country.
"I speak to you today, my family and my tribe... to assure you that the sedition has been nipped in the bud, and that our proud Jordan is safe and stable," King Abdullah II said in an address read out in his name on state television, a day after an official news blackout on the affair. "The challenge over the past few days was not the most difficult or dangerous to the stability of our nation, but to me, it was the most painful," he said, according to an official English translation released after the broadcast.
"Sedition came from within and without our one house," he added. In using the words "from within," it was not clear whether the king was referring to actors in the royal family or the wider kingdom.
Foreign Minister Ayman Safadi on Sunday charged that the plotters had linked up with foreign parties, but had declined to identify them. Reacting to the events, King Abdullah II said he felt "shock, pain and anger, as a brother and as the head of the Hashemite family, and as a leader of this proud people".
Prince Hamzah was appointed crown prince in 1999 in line with his father's wishes, but King Abdullah II stripped him of the title in 2004 and named his eldest son in Hamzah's place. After claiming he was put under house arrest Saturday, Prince Hamzah had made extensive use of traditional and social media to lash out against his situation. He accused Jordan's rulers of corruption and ineptitude in a video message published by the BBC on Saturday.
But after a statement voicing his loyalty to the king on Monday, King Abdullah II said Wednesday that Hamzah had offered his support for the monarchy.
"Hamzah today is with his family, at his palace, in my care," King Abdullah II said in his address, according to Agence France-Presse (AFP). "Prince Hamzah pledged before the family to follow in the steps of the ancestors, remain loyal to their mission, and to put Jordan's interest, constitution, and laws above all considerations."