The man is thought to be responsible for kidnapping Jordanians and Arabs and robbing commercial trucks driving between the kingdom and Iraq.
"He has committed several crimes," said the announcement on Jordanian state television.
It said Jordanian intelligence agents have taken the suspected militant into custody, but it did not say when or provide other details.
The announcement said details of his operations would be aired on television in a special program Thursday night (local time).
No other details were immediately available.
The top leader of Al-Qaeda in Iraq, Jordanian-born Abu Musab al-Zarqawi, has claimed responsibility for several terror attacks against his native country, including triple hotel blasts last November 9 in the Jordanian capital which killed 63 people, including three Iraqi suicide bombers.
Al-Zarqawi's group has claimed responsibility for scores of kidnappings, beheadings and suicide bombings in neighbouring Iraq.
The group opposes Jordan's moderate stance on Islam, its longtime alliance with the United States and the peace treaty it signed with Israel in 1994.
A Jordanian military court has sentenced Al-Zarqawi to death three times for terror attacks, including the October 2002 slaying of US official Laurence Foley, who was gunned down outside his Amman home.