Ecuador's former president Lucio Gutierrez, who has been living in exile in Colombia, was arrested when he returned to Ecuador to retake power.
Mr. Gutierrez was detained minutes after his plane landed Friday evening.
The former president refuses to acknowledge his successor, once his own Vice President, Alfredo Palacio.
In a news conference in Colombia Thursday, Mr. Gutierrez renounced his asylum in Colombia and pledged to take all legal and constitutional actions to regain the presidency.
Ecuador's Congress removed Mr. Gutierrez from office in April, after weeks of mass protests.
Critics had demanded his resignation for what they called an abuse of power after he packed the Supreme Court with his allies.
Mr. Gutierrez was granted asylum in Colombia earlier this month.
Some information for this report provided by AP and Reuters.