The man, who identified himself as Iraqi national Ziad Khalaf al-Karbuli, said during the 15-minute tape that he shot to death Khalid Dassuki "with my personal revolver" in September in Iraq.
"I fired two shots at his head," al-Karbuli said.
He also claimed responsibility for the abduction of the two Moroccans in October and said they were handed over to al-Qaeda in Iraq, the group run by Jordanian-born fugitive Abu Musab al-Zarqawi.
State television, quoting a security source, identified al-Karbuli as a customs employee on the Iraqi border and said he was arrested in a joint operation by the intelligence forces and army special forces after drawing him out of Iraq.
Al-Karbuli also confessed during his interrogation by the Jordanian judicial authorities of having abducted an aide to a former Iraqi finance minister who was on his way from Jordan to Iraq, the security source was quoted as saying.
According to the source, al-Karbuli also confessed that he killed four Iraqi national guards, television reported.
The Jordanian authorities announced al-Karbuli's arrest on Monday and identified the suspect as "an important figure in the al-Qaeda in Iraq organisation".