The officials said Mahboobullah Mohebi was killed when a sticky bomb, attached to his car by unknown assailants, went off on Tuesday.
The blast occurred while Mohebi was traveling with his security guards.
No group has yet claimed responsibility for the attack, which also left two guards wounded.
Last week, an Afghan government prosecutor was killed in eastern Kabul while he was on his way to work.
The increase in violence in Afghanistan comes while the government and the Taliban militant group reached a preliminary deal earlier this month that sets out rules for further talks, the first written agreement between the two sides since the US-led invasion of 2001.
Representatives from the government in Kabul and those from the Taliban held the first round of intra-Afghan negotiations in the Qatari capital of Doha on September 12. The talks are also attended by international organizations and the United States.
The intra-Afghan talks were set to take place in March, but were repeatedly delayed over a prisoner exchange agreement made as part of a deal between the Taliban and the United States.
Under the deal, signed on February 28, the Taliban agreed to halt their attacks on international forces in return for the US military's phased withdrawal from Afghanistan and the prisoner exchange with Kabul.
But official data shows that violence has increased by 70 percent in Afghanistan since the US-Taliban deal.