The move is within the framework of comprehensive joint investigations conducted by the security apparatuses, which resulted in the arrest of royal family member Sharif Hassan Ben Zeid and former minister Bassem Awadallah, among others, according to the state-run Petra news agency.
This file handout picture released by the Jordanian news agency Petra on January 12, 2012 shows Prince Hamzah, half-brother of Jordan's King Abdullah, and his new wife Princess Basma Otoum (right) posing for a picture during their wedding ceremony at the Royal Palace in Amman.
Jordan's army chief said on Saturday that Hamzah was not under arrest, but had been asked to stop "some activities that could be used to shake the stability and security of Jordan".
Abdullah had appointed Hamzah, a popular figure close to tribal leaders, crown prince in 1999 in line with Hussein's dying wishes, but stripped him of the title in 2004 and gave it to his eldest son Hussein.
Sherif is a title given to those close to the royal family in Jordan.
Mr Safadi said officials had tried to discourage the prince rather than take legal action against him, but that Prince Hamzah had "dealt with this request negatively".
These included a foreign intelligence agency contacting Hamzah's wife to organise a plane for the couple to leave Jordan, he said.
Special Assistant to the Prime Minister of the Middle East Tahir Ashrafi has expressed Islamabad's solidarity with Jordanian authorities, following an alleged plot to destabilise the country.
Authorities then stepped in to cut communications between Prince Hamzah and the foreign parties.
Majali told Roya "No one will be more compassionate to Prince Hamzah than his big brother His Majesty King Abdullah II".
While Hamzah denies any wrongdoing, he denounced the ruling government in the video, saying, "I am not the person responsible for the breakdown in governance, for the corruption, and for the incompetence that has been prevalent in our governing structure for the last 15 to 20 years, and has been getting worse by the year".
The US state department has already offered the king, who has cultivated close relations with Washington and been a key ally in the war against Islamic State, its "full support".
Jordan's traditional allies, including the US, Saudi Arabia and Egypt, have expressed support for King Abdullah. The country borders Israel, the occupied West Bank, Syria, Iraq and Saudi Arabia.
Senior Emirati official Anwar Gargash said on Twitter Jordan's "wise policy to build bridges in a turbulent region was not an easy choice but was, and remains, the necessary direction".
"We support the steps taken by King Abdullah to maintain Jordanian national security, stressing that Jordan's security and stability is a supreme Palestinian interest". Several high-profile figures were also detained.
He played a key role pushing for economic reforms before he resigned in 2008 amid criticism over alleged interference in sensitive political and economic issues.
Jordan Begins Arrests in Possible Plot Against King
Abdullah has ruled Jordan since the 1999 death of of his father, King Hussein, who ruled the country for close to a half-century. The Gulf Cooperation Council also reaffirmed support for "all decisions and measures" taken by Abdullah.
Jordan arrests ex-palace aide, others for ‘security’ reasons
Arrests by senior officials and members of the royal family are rare in Jordan , considered one of the most stable Arab countries. Two people familiar with the situation told Reuters security forces had arrived at his small palace and begun an investigation.