Libyan officials are trying to locate Muammar Gaddafi's wife and three of his children who are missing from their refuge in neighbouring Algeria.
Officials confirmed the late dictator's second wife, Safia, daughter Aisha, and sons Hannibal and Muhammad had fled the upmarket coastal region of Staoueli, close to Algiers, where they had lived since escaping from Libya in 2011.
Libya's foreign minister Mohammed Abdelaziz said in Doha some of the family had moved to Oman. He said an official statement by the three countries involved - Libya, Algeria and Oman - would be issued soon.
Gaddafi's most prominent son, Saif al-Islam, remains in custody in the Libyan town of Zintan, and his brother Saadi is under house arrest in Niger.
Libya has already put Aisha and Hannibal on Interpol's red notice list, obliging member states to arrest them. Omani local daily Al-Shabiba said members of Gaddafi's family have been in Oman since October.
It cited a foreign ministry official saying that the Gulf state did not want to "show off" with an action prompted by "humanitarian" motives.
Aisha's Israeli lawyer, Nick Kaufman, would not comment on reports of their flight, but said he was representing her in efforts to get the international criminal court to investigate the killing of her father.
"I was indeed retained by Aisha Gaddafi for one discrete issue; namely, seeking the opening of an investigation at the ICC into the murder of Muammar Gaddafi," he said.
The news of their disappearance comes as Egypt and Morocco announce the arrest of several prominent Gaddafi-era figures who had fled Libya, including Gaddafi's cousin Ahmed Gaddafi al-Dam, captured in Cairo.
The three siblings fled Libya with Safia during the Arab spring revolution as rebel forces entered Tripoli in August 2011.
Aisha lost her husband and two children in the Nato bombing of Tripoli in 2011 and gave birth to a baby girl the day after arriving in Algeria.
Of the three, Libyan authorities are keenest to arrest Hannibal, former head of Libya's maritime transport authority and part of Gaddafi's inner circle.
Additional reporting by Agence France-Presse