NAIROBI, Kenya – The American author of a best-selling book attacking Barack Obama as unfit for the presidency was being deported from Kenya on Tuesday, a criminal investigations official said.

Jerome Corsi, who wrote “The Obama Nation: Leftist Politics and the Cult of Personality,” was picked up by police Tuesday for not having a work permit, said Carlos Maluta, a senior immigration official in charge of investigations.

He was briefly detained at immigration headquarters before being brought to Jomo Kenyatta International Airport for deportation, said Joseph Mumira, head of criminal investigations at Jomo Kenyatta International Airport.

It was not immediately clear when he would fly out. A message left on Corsi's mobile phone was not returned.

Obama spokesman Bill Burton said the campaign had no comment.

Corsi had been scheduled to launch his book Tuesday in Kenya, where the Democratic U.S. presidential candidate is wildly popular. Obama's late father, whom he barely knew, was a Kenyan economist and the candidate is considered by many Kenyans as a native son. Minibuses are emblazoned with his picture and vendors sell T-shirts bearing his image.

Obama was born in Hawaii, where he spent most of his childhood raised by his mother, a white American from Kansas.

Corsi's book claims the Illinois senator is a dangerous, radical candidate for president and includes innuendoes and false rumors – that he was raised a Muslim and attended a radical black church.

Obama is a Christian who attended Trinity United Church of Christ in Chicago, and his campaign picks apart the book's claims on the Obama campaign's rumor-fighting Web site, FightTheSmears.com.

According to a statement announcing Corsi's visit, he arrived last week at the invitation of Christian missionaries concerned about the rise of Islam. Corsi was planning to file daily dispatches all week, the statement said.

Obama's Kenyan uncle, Said Obama, said he was unaware of Corsi's detention and had no comment. A government spokesman did not return calls for comment.

Associated Press writer Elizabeth A. Kennedy contributed to this report.