TRIPOLI - Libya has arrested a female Australian lawyer from the International Criminal Court for trying to pass "dangerous" documents to Seif al-Islam, detained son of slain leader Moamer Kadhafi, the ICC's Libyan representative said on Saturday.

"During a visit (to Seif on Friday), the lawyer tried to deliver documents to the accused, documents that have nothing to do with his case and that represent a danger to the security of Libya," Ahmed al-Jehani said.

The lawyer, named as Melinda Taylor, was part of a four-member ICC delegation that received permission from Libya's chief prosecutor to visit Seif in Zintan, southwest of Tripoli, where he is being detained.

Jehani said she is "under house arrest in Zintan, not in prison," and is being questioned by the authorities.

The ICC's spokesman in The Hague could not be reached for comment.

Seif, 39, has been in custody in Zintan since his arrest on November 19 in the wake of the uprising that toppled his father rule after more than 40 years in power.

The ICC wants both Seif and his late father's spymaster, Abdullah Senussi, for crimes against humanity committed while trying to put down last year's bloody revolt.