An Australian activist and freelance journalist working in East Timor has been arrested by police after a raid on his house.

Julian King, 43, is being held at Dili's police headquarters after police searched his home early yesterday morning.

Mr King was apprehended by police on Wednesday night and told he had 48 hours to leave the country.

He was arrested while he was on the way to visit his lawyer.

Mr King says he has not been charged.

"They claim they found a small box of ammunition in my bedroom and that's the reason that they have arrested me," he said.

"However, I found out today that they also took all of my research documents.

"A lot of these documents are classified documents that reveal corruption in the United Nations and members of the Government here in East Timor."

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