Jordan's Crown Prince Hamzah
Jordan's Crown Prince HamzahREUTERS/Ali Jarekji

A Jordanian court on Thursday upheld the conviction of two former senior officials on sedition and other charges connected to an alleged plot against the kingdom involving the half-brother of King Abdullah II, The Associated Press reported.

Bassem Awadallah, who has US citizenship and once served as a top aide to the king, and Sharif Hassan bin Zaid, a member of the royal family, were sentenced to 15 years in prison in July by a state security court. They were accused of conspiring with Hamzah, a former crown prince, and of seeking foreign assistance.

The two pleaded not guilty to sedition and incitement charges in June after being swept up in a wave of arrests in April.

On Thursday, the Court of Cassation dismissed an appeal field by lawyers for the two men, saying they were convicted in accordance with the law, according to AP.

The government has accused Hamzah -- a former crown prince who was sidelined as heir to the throne in 2004 -- of involvement in a conspiracy to "destabilize the kingdom's security" and arrested at least 16 people.

Hamzah has emerged as a vocal critic, accusing Jordan's leadership of corruption, nepotism and authoritarian rule.

In a video he sent to the BBC in April, he lashed out at "incompetence that has been prevalent in our governing structure for the last 15 to 20 years and has been getting worse".

"No-one is able to speak or express opinion on anything without being bullied, arrested, harassed and threatened," he charged.

Following the attempted coup against King Abdullah II, roads to Hamzah’s palace were blocked with security services patrolling entrances to the capital city of Amman.

He subsequently signed a letter pledging his loyalty to the king following mediation by an uncle.

Hamzah has denied being part of any conspiracy and said he was being targeted for speaking out against corruption.