At the time of the hacks, Lama Fakih said her work included covering the fighting between Israel and Hamas in Gaza and an investigation into the devastating 2020 Beirut port explosion.
A regional director of Human Rights Watch who investigated Israel's conflict with Hamas in Gaza and the Beirut port explosion had her phones hacked with spyware made by the Israeli company NSO.
The cellphones of Lama Fakih, who is based in Lebanon and oversees the US-based group's response for countries ranging from Syria and Israel to Myanmar and Ethiopia, was targeted five times last year, HRW said on Wednesday.
Fakih's work includes exposing rights abuses in armed conflict, unrest and humanitarian disasters, and "may have attracted the attention of various governments, including some that are suspected NSO clients", the rights group said.
At the time of the hacks, Fakih said her work included covering the fighting between Israel and Hamas in Gaza and an investigation into the devastating 2020 Beirut port explosion.
She said there was no way to tell whether there was a link between that work and the hacking.
NSO may investigate
HRW said it was told by NSO that the company was not aware of any active NSO customer using its technology against an HRW staff member, and that it would assess whether an investigation was warranted.
"NSO believes there should be an international regulatory structure put in place to ensure the responsible use of cyber intelligence tools," an NSO Group spokesperson said.
"However, any call to suspend these life-saving technologies until such a structure exists is naive and would only benefit the terrorists, paedophiles and hardened criminals who will evade surveillance and apprehension."
Last year the US Commerce Department took steps to make it harder for US companies to do business with NSO, based on a finding that the company's software was used to "maliciously target" officials, journalists, activists and business people.
Last month, a group of US lawmakers asked the Treasury Department and State Department to sanction NSO and three other foreign surveillance companies they say helped authoritarian governments commit human rights abuses.
In November, Apple sued NSO, saying that it violated US laws by breaking into the software installed on iPhones.