Mr Ben Ali's former adviser Abdelaziz bin Dhia and former Interior Minister Abdallah Qallal are now under house arrest, state media have reported on January 23.

Meanwhile, the owner of a private TV station has reportedly been arrested for "treason" for encouraging violence. The news came as a protest march against the interim government reached the capital Tunis.

Protesters want the prime minister, who served under Mr Ben Ali, to resign. Prime Minister Mohamed Ghannouchi has pledged to quit after elections, which are expected within six months.

On January 23’s night, hundreds of people broke a curfew to continue their protest camped outside Mr Ghannouchi's office.

Last week, some 33 members of Mr Ben Ali's family were arrested as they tried to leave the country. State TV showed what it said was gold and jewellery found during raids on their properties.

It is not known which family members of Mr Ben Ali - who has fled to Saudi Arabia - have been held.