Ghulam Hazrat, the driver's uncle, said his nephew had tried to disarm the gunmen as they attempted to abduct Egreteua and another Westerner.
"He grabbed the gun of one of the kidnappers. The other shot him dead with five bullets. At this time one of the foreigners ran away and they put the other in the car, kicking him badly."
The kidnapping comes less than 10 days after a Briton and South African were shot dead and two weeks after another attack in which a female British aid worker was killed in Kabul.
Afghanistan is experiencing its highest level of violence since 2004, when US-led forces pushed the Taliban from power.
Opposition fighters have seized dozens of foreigners and hundreds of Afghans in the last three years.
Businessmen and wealthier Afghans have been kidnapped by criminal gangs looking for ransom payouts.
Most have been released unharmed but several have been killed.