Royal family member Sharif Hassan Ben Zaid is still in detention, so is a confidant of the king, Bassem Awadallah.
Jordan has released 16 people linked to a rift in the royal family that rattled the country, but a member of the royal family and a former adviser to the king remained in detention.
Security sources said those released were mostly personal aides to former heir Prince Hamzah, King Abdullah's half-brother, who had said in an April video he was banned from leaving his home and accused the country's rulers of corruption.
The two royals last week made their first joint appearance since the feud earlier this month.
With mediation by the royal family, Hamzah had pledged allegiance to the king, days after the military ordered him to stop actions that it said undermined Jordan's security.
Thursday's move came after calls from tribal families for the release of detainees, the sources said.
No royal pardon yet
State prosecutor Brigadier General Hazem al Majali said the decision to release the 16 "at this time in the investigation" was taken at the request of the king.
Wafaa Bani Mustafa, a former parliament member who attended a meeting with the king on Thursday, said they were released to spend the holidays with their families while the investigation proceeds.
They have not yet received royal pardons, she said.
Royal family member Sharif Hassan Ben Zaid remained in detention, as did Bassem Awadallah, a confidant of the king who was finance minister and advisor to Saudi Crown Prince Mohammed bin Salman.
State news agency Petra, citing the public prosecutor in the state security court, said they were not freed because "their roles ... and level of agitation differed" from the others.
Bid to destabilise kingdom?
Earlier Abdullah, in a statement released by the royal court, said he had asked authorities to release "brothers" who were "misled, wronged, dragged behind this sedition" so they could be with family as soon as possible during the Muslim fasting month of Ramadan.
The king made the request after lobbying by a number of key figures from across Jordan who asked him to show tolerance, state TV Al Mamlaka and official Petra news agency reported.
Eighteen suspects were arrested after authorities on April 3 announced they had foiled a bid to destabilise the kingdom.
Deputy Prime Minister Ayman Safadi called the bid a "wicked plan."
The case was handed over to the State Security Court – which has both military and civilian judges and deals with high treason, espionage, drug trafficking, counterfeiting money and terrorism.
The court began its investigations on April 14, after Amman prosecutor Hassan Abdallah issued a gag order banning the publication of any information pertaining to the case.
Jordan's media was instructed to wait for official statements before publishing anything about those arrested.
The government accused the former crown prince, who was sidelined as heir to the throne in 2014, of involvement in a conspiracy to "destabilise the kingdom's security."
News of the alleged plot broke earlier this month, and at the time Abdullah's half-brother Prince Hamzah was suspected of involvement.
But authorities said later he would not stand trial, as his case had been resolved within the royal family.
It came after the king broke several days of silence to tell the nation the worst political crisis in decades was over and the pair later appeared together in public.
After claiming he was put under house arrest on April 3, 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 that same day.
But later on Abdullah said Hamzah had offered his support and loyalty for the monarchy and was now under his "protection."
In the statement released on Thursday by the royal court, Abdullah said "what took place was painful."
"The sedition, as I have said has been stopped, but if it had not been stopped at the onset, it could have taken the country in a difficult direction, God forbid," he said.