A report by the group accused Israel and Egypt of barring human rights workers from entering into the blockaded Gaza Strip.
An international right group released a report on Monday, accusing Israel, Egypt and Hamas of blocking humanitarian workers from entering Gaza strip.
In a 47-page report, the New York based right group, Human Right Watch (HRW) said the travel restrictions have been imposed by the Israeli regime since 2008.
According to the group, Egypt has prevented them and also London-based Amnesty International from entering Gaza from its territory since 2012.
Israel and Egypt have imposed a blockade on Gaza, home to nearly two million people, since Hamas took over the territory in 2007.
International rights groups have accused both sides of committing war crimes, while the International Criminal Court is conducting a preliminary investigation into possible wrongdoing by both sides.
"If Israel wants the ICC prosecutor to take seriously its argument that its criminal investigations are adequate, a good first step would be to allow human rights researchers to bring relevant information to light," said Sari Bashi, Israel and Palestine advocacy director at HRW.
The group also criticised Hamas for its refusal to cooperate with foreign rights investigators.
It said Hamas has failed to protect local human rights workers from retribution and sometimes arrested or harassed its critics.
TRT World's Editor-at-large Ahmed al Burai has more details.
Israel denies HRW's accusations
The Coordinator of Government Activities in the Territories (COGAT), the Israeli defence body that coordinates access to Gaza, denied the findings of the report.
Cogat said in a statement that it allows around 1,000 people to cross through the border each day for a variety of purposes, including business, medical treatment and academic studies.
It accused Hamas of trying to exploit Gaza civilians travelling through Israel for military purposes.