International human rights groups on Friday called on Saudi Arabia to allow independent investigators into the country to probe fresh accusations of torture and abuse of human rights activists.
The calls by Amnesty International and Human Rights Watch (HRW) follow a similar appeal in November and December from the watchdogs which said investigations by Saudi Arabia itself had not been satisfactory.
London-based Amnesty said it has obtained new reports concerning 10 human rights activists who had been "tortured, sexually abused and subjected to other forms of ill-treatment" in detention.
"One woman activist was wrongly told by an interrogator that her family members had died and was made to believe this for an entire month", while two others "were forced to kiss each other while interrogators watched", Amnesty said.
"We are extremely concerned about the well-being of these activists, who have been in arbitrary detention for around nine months simply for standing up for human rights," Amnesty's Lynn Maalouf said.
"The Saudi Arabian authorities have repeatedly proven themselves unwilling to effectively protect detainees from torture, or to carry out impartial investigations into claims of torture in custody," she said.
Amnesty called on Saudi Arabia "to give independent monitoring bodies immediate and unfettered access to the detained activists".
HRW issued a similar appeal in a separate statement on Friday.
"Saudi authorities should immediately allow independent international monitors to enter Saudi Arabia and meet with detainees, including those who have alleged torture," it said.
"Saudi Arabia's internal investigations have little chance of getting at the truth of the treatment of detainees," Michael Page, Human Rights Watch Middle East and North Africa division deputy director, said.
In November, Saudi Arabia dismissed as "false" and "unfounded" reported by Amnesty and HRW that three women activists had been tortured and sexually harassed in detention.
The reports came as Saudi Arabia faces intense global criticism over the killing of insider-turned-critic Jamal Khashoggi in its Istanbul consulate on October 2.
More than a dozen activists were arrested in May -- just before the historic lifting of a decades-long ban on women drivers the following month.
Many of them were accused of undermining security and aiding enemies of the state. Some were subsequently released.