The Human Rights Watch (HRW) delegation is on a two-week visit to Saudi Arabia to discuss its judicial system and women's rights.
The New York-based group arrived in Riyadh last week and has already met Foreign Minister Saud al-Faisal, Justice Minister Abdullah al-Sheik and prison officials.
This is the first time an international independent human rights group has been allowed into the fiercely conservative Gulf country.
HRW wants Saudi Arabia to open up its justice system, which it accuses of human rights abuses including depriving suspects of their legal rights and holding people in prolonged solitary confinement.
Reform rumours
Hanny Megally, who is leading the five-member HRW team, says he wants to find out about Saudi Arabia's plans for political reform, and whether it is considering elections for the consultative Shura council, now an appointed body.
Western diplomats say there have been rumours of impending change since Crown Prince Abdullah last month called for political reforms in the Arab world, including greater popular participation in politics.
A United Nations human rights investigator, who visited Saudi Arabia on the first trip of its kind last October, has said judicial reforms are being held back by internal resistance to change.
Since the 11 September 2001 suicide attacks in New York and Washington, Saudi Arabia has come under increasing pressure from the West to introduce democratic reforms.
The US says 15 of the 19 hijackers were Saudi nationals.
In December the US pledged $29m in an attempt to strengthen democracy across the Middle East.
But critics say Washington is ignoring human rights abuses in Saudi Arabia in order to win Saudi help in opposing Iraqi leader Saddam Hussein.