THE HAGUE, Netherlands - The International Criminal Court granted Libyan authorities more time Tuesday to answer its questions about Moammar Gadhafi's son and one-time heir apparent, who is wanted by the court but is being held by Libyan fighters.

Libya's new rulers said Monday they need three more weeks to respond to questions about Seif al-Islam Gadhafi that the ICC judges asked on Dec. 6 "due to the security situation" in the North African nation.

Judges granted them until Jan. 23, saying in a written decision that three extra weeks "would cause an undue delay."

The international court in June charged Seif, along with his father and former Libyan intelligence chief, Abdullah al-Senoussi, with crimes against humanity, including multiple murders allegedly committed during the former regime's brutal crackdown on dissent.

Seif was arrested in November by fighters in Libya's remote southern desert. He has been held largely without access to the outside world ever since and Libyan authorities say they want to put him on trial at home, despite an arrest warrant issued by the ICC.

The case against Moammar Gadhafi was halted after he was captured and killed by rebels in October. Al-Senoussi's whereabouts are unknown.

Judges have asked Libya whether Seif was arrested based on the ICC warrant, whether he was being held incommunicado, and whether ICC officials could visit Seif to check on his health and ask if he wants legal representation.

His sister, Aisha Gadhafi, expressed disappointment at Libya's failure to meet the original deadline for responding.

Nick Kaufman, Aisha Gadhafi's lawyer, said she "regrets that her brother Seif al-Islam continues to be denied his basic human rights, namely access to a lawyer, access to a competent judicial authority charged with reviewing the conditions of his detention and communication with his family."

Libya's request for more time came days after the country's new rulers hosted a visit by Sudan President Omar al-Bashir, despite a long-standing arrest warrant issued by the ICC that accuses al-Bashir of genocide and other crimes in Sudan's Darfur region.

The ICC is a court of last resort, meaning it only tries cases other nations cannot or will not try. Even so, Libyan authorities must still seek the court's clearance to prosecute Seif and persuade its judges that he will get a fair trial on the same charges he would have faced in The Hague.