Israeli police briefly rearrested freed Palestinian prisoner Maher Younis for incitement, according to local media on Sunday.
Israeli public broadcaster KAN said Younis, 64, was taken into custody for questioning on incitement after he wrote posts on social media viewed by the police as encouraging "acts of terror."
He was later released, the broadcaster added.
Last week, Younis was set free from prison after serving 40 years in Israeli jail.
He was arrested on January 18, 1983 and was sentenced to a life-term that was defined to 40 years by Israel.
Israel holds nearly 4,700 Palestinians, including 150 children and 29 women, according to official Palestinian figures.
