The International Criminal Court on Wednesday rejected a final bid by Tripoli's lawyers to try slain dictator Moamer Kadhafi's son Seif al-Islam in Libya, meaning he must now be transferred to The Hague.
Seif's transfer to face charges relating to the bloody repression of the 2011 uprising that toppled his father is however a moot point as he is being held by a Libyan militia rather than any central authority in the chaos-wracked country.
The presiding ICC judge Erkki Kourulas struck down four grounds of appeal before the world's war crimes court, saying "in the present case the Appeals Chamber confirms the (pre-trial chambers') decision and dismisses the appeal."
ICC pre-trial judges a year ago rejected Tripoli's request to put him in the dock in Libya, saying the country was unable to give him a fair hearing.
This included Tripoli's inability to transfer Seif, Kadhafi's one-time heir apparent, to the Libyan capital from his prison in the hilltop stronghold of Zintan, where he is currently being held by militia members.
Tripoli appealed the original decision a few days later in June.
Seif, 41, and Kadhafi's former spy chief Abdullah Senussi, around 64, have been charged for their roles in violent attempts to put down the 2011 uprising in the desert country that eventually toppled Kadhafi's regime.
Seif appeared on May 11 by video link in a Tripoli court from Zintan, where he has been held since his capture by rebels in November 2011.
His court-appointed lawyer was unable to attend Sunday's hearing, so the trial was adjourned to May 25 to allow him to help his client.
"The ICC Appeals decision today reinforces Libya's long overdue obligation to surrender Seif Kadhafi to The Hague for fair trial," Human Rights Watch's international justice director Richard Dicker said.