U.S. freelance journalist William Nessen was detained by immigration officials upon arrival in the Indonesian city of Medan Wednesday and his deportation was due later in the day.
Nessen arrived in the North Sumatra capital en route to nearby Aceh province, where he said he would visit his wife.
"I plan to meet my wife, who is an Acehnese," he was quoted by the Detikcom news website as saying.
Nessen wrote with the separatist Free Aceh Movement (GAM) in 2003 when Jakarta launched an offensive to crush rebellion in the province.
He surrendered himself to the Indonesian military but local authorities charged him with immigration violations for failing to show his passport and other documents.
He was sentenced to one month for the immigration charge but was freed from spy charge.
He was released on Aug. 3, 2003, but has since an entry ban been imposed against him.