MoI spokesman Najib Danish confirmed that Rafiullah Gul Afghan was shot dead on Saturday evening in Kabul city.
He said the assassination was carried out by unknown gunmen in Bostan Road in the vicinity of the 17th police district.
Danish further added that the driver of the former Senator was also killed in the attack.
According to Danish, an investigation is underway regarding the incident.
No individual or group has so far claimed responsibility behind the attack.
Rafiullah Gul Afghan was serving as the deputy chairman of the Afghan Senate House, Meshrano Jirga.
He was also one of the members of Jamia-e-Islami Party of Afghanistan.
According to reports, Rafiullah Gul Afghan was working as an advisor to the Chief Executive when he was murdered by the gunmen.