Israeli troops rearrested a senior Hamas official overnight, along with his son, a military spokeswoman told AFP Tuesday.
She said the two were detained due to their "links to Hamas."
Hassan Yusef was released from prison in early August after serving a six-year term for "membership of a terrorist organisation," but was rearrested in early September and then released a week later.
"The occupation raided Hassan Yusef's house in Ramallah and arrested him with his son Owais," a Hamas official who spoke on condition of anonymity told AFP.
Hamas condemned the move and warned it would have "consequences."
"We strongly condemn this arrest campaign against leaders of the movement, particularly Sheikh Hassan Yusef," Hamas official Ismail Abu Radwan told AFP in Gaza.
Yusef was freed on August 4 as part of a mass release of Israeli and Palestinian prisoners due to overcrowding. He had six weeks left of his sentence.
Last March, Yusef disowned another son after he admitted to having spied on Hamas for Israel and played a major role in the arrest of senior militants.
Mosab Hassan Yusef, 32, said he was a top informer for Israel's Shin Bet internal security agency and was known by the codename "The Green Prince."
He converted to Christianity 10 years ago and now lives in California.
He reportedly worked for the Shin Bet at the height of the second Palestinian intifada, or uprising, that began in 2000, when Hamas carried out dozens of suicide bombings and Israel waged all-out war on the Islamist movement.
Hamas has said the elder Yusef worked entirely in the public political wing of the movement. He was elected to the Palestinian parliament in 2006, while in Israeli custody.
