Unidentified individuals opened fire on the vehicle carrying adviser Serhiy Shefi — who is also a close friend of the president — as it travelled between two villages outside the capital, Kyiv, on Wednesday.
Ukrainian officials said the attack could have been carried out as a response to the reform.
The aide was reported not to have been hurt, although his driver was wounded. President Zelenskyy himself was in New York for the United Nations General Assembly.
Ukraine’s Interior Ministry on Thursday said police were searching for weapons and interviewing possible witnesses who were picking mushrooms nearby
Zelensky came to power on a promise he would fight corruption and tackle Ukraine's powerful oligarchs.