A videotape broadcast on Arabic television channel Al-Jazeera Friday, showed a group of black-clad masked militants standing behind a man identified as diplomat Mohammed Qutb.
The group says the abduction is in response to Cairo's willingness to provide Iraq's interim government with security expertise.
The Egyptian embassy in Baghdad has confirmed the diplomat's abduction.
Meanwhile, efforts are continuing to free seven truck drivers kidnapped by another militant group in Iraq.
The militants, threatening to behead the three Kenyans, three Indians and an Egyptian, have issued a new 48-hour deadline to the hostages' Kuwaiti employer. They have also made new demands, including compensation to the families of those killed in clashes with U.S. forces in Fallujah.
And Bulgarian officials are continuing to investigate whether a decapitated body discovered Thursday in the Tigris River is that of a second Bulgarian hostage feared killed by militants. Bulgarian officials confirmed Thursday that an earlier headless corpse was that of another missing Bulgarian.
Some information for this report provided by AP and Reuters