Mursal Nabizada, a former lawmaker in the Afghan parliament before the Taliban's takeover, was shot dead in her home, police said on Sunday.
One of her bodyguards was also killed in the attack, which took place overnight. A second security guard was injured, along with her brother. Police did not give details of any assailants.
Nabizada is one of the few former lawmakers to stay in Afghanistan after hardline conservative Taliban militants took complete control of the country following the departure of the US and its military allies.
Her death marks the first time that a politician from the previous political establishment has been killed under Taliban control.
First ex-lawmaker killed since Taliban takeover
The 29-year-old lawmaker was elected in 2019 to represent the city of Kabul. She had served as a member of the parliamentary defense commission as well as working for a private NGO, the Institute for Human Resources Development and Research.
After the return of the Taliban in the summer of 2021, she continued doing NGO work, which she discussed around four months ago during an appearance on local TV.
She also condemned the Taliban's increasing restrictions on Afghan women's freedoms.
Police spokesperson Khalid Zadran said that the motive for the killing was unclear, however, police also said that a third bodyguard had fled the murder scene with money and jewelry.
Taliban crackdown on women
Thousands of people fled Afghanistan as Taliban forces rapidly took control back from a weakened US-backed government.
Many feared a return to the Taliban's oppressive Islamist rule that had marked their time in power in the late 1990s.
Despite promises from the Taliban to maintain some of the freedoms that people, especially women, had experienced in the two decades since the allied invasion removed the militants from power in the first place, many of these promises have gradually proven to be meaningless.
In late December, the Taliban declared that women will no longer be allowed to go to university, effectively limiting girls' education to a maximum of sixth grade.
A recent ban on women working with international NGOs has also seen much necessary support cease its work in the impoverished country.