The governmental Saudi Human Rights Commission arranged access to a wide range of high-level officials, while several ministers expressed their desire to invite HRW back to the kingdom to discuss the findings in detail, the statement said.

But the rights group which has repeatedly slammed the human rights record in the ultra-conservative kingdom said the movement of its mission was restricted.

"By restricting our access to prisons and withholding general permission to observe trials, however, the Saudi government gave the appearance that it still has much to hide," Whitson said.

The statement claimed that HRW researchers were placed under 24-hour surveillance, but however listed a number of findings.

In a visit by the team to Al-Ha’ir prison south of Riyadh, prisoners reported that they had "suffered physical abuse, had remained imprisoned beyond the expiry of their sentences, particularly in the case of foreign prisoners, and had endured unexplained and lengthy delays before or during their trials."

It charged that the secret police holds thousands of security detainees without trial, charge or access to counsel for months and years.

HRW said that interviews held with some 100 women from different walks of life also documented how male guardianship of adult women denies women the right to employment, education, health, and freedom of movement.

"Government policy often explicitly requires male consent for a range of everyday activities. This system, premised on the idea that women have limited or no legal capacity to act on their own behalf, affects all Saudi women across economic or social divides," it said.

 HRW urged Saudi Arabia to lift travel bans on prominent critics saying such restrictions violate international law.