Political prisoners in Saudi Arabia are said to be suffering from malnutrition, cuts, bruises and burns, according to leaked medical reports that are understood to have been prepared for the country’s ruler, King Salman.

The reports seem to provide the first documented evidence from within the heart of the royal court that political prisoners are facing severe physical abuse, despite the government’s denials that men and women in custody are being tortured.

The Guardian has been told the medical reports will be given to King Salman along with recommendations that are said to include a potential pardon for all the prisoners, or at least early release for those with serious health problems.

Ha’er prison in Saudi Arabia. Photograph: Faisal Al Nasser/Reuters

These options are part of a substantial internal review said to have been ordered by the king, who approved the commissioning of examinations of up to 60 prisoners, many of them women, for a report to be circulated around the royal court, a source said.

Some of the assessments were leaked to the Guardian, which asked the Saudi government to comment on the medical reports more than a week ago. A spokesman declined to discuss the issue, despite being given repeated opportunities to do so. Officials did not challenge the authenticity of the reports.

The Guardian has been able independently to verify the accuracy and contents of one of the examinations. The conditions of other individuals, as described in the documents, are consistent with reports that have emerged involving claims of torture, though the Guardian has not been able to corroborate the details.

Pressure on Saudi Arabia over the detention and treatment of political prisoners has been growing in recent months amid claims that some female activists have been subjected to electric shocks and lashings in custody.

With the kingdom also reeling from the aftermath of the murder of the dissident journalist Jamal Khashoggi, King Salman is said to have ordered a review of the decision to arrest and detain about 200 men and women in a crackdown ordered by his heir, Crown Prince Mohammed bin Salman.

According to a source with knowledge of the review, the royal court set aside objections from Prince Mohammed’s aides and sought brief medical examinations on a number of detainees to get a snapshot of their health.

The men believed to have been examined include Adel Ahmad Banaemah, Mohammed Saud Al Bisher, Fahad Abdullaziz Al-Sunaidi, Zuhair Kutbi, Abdullaziz Fawzan al-Fawzan and Yasser Abdullah al-Ayyaf.

The Guardian understands the women include Samar Mohammad Badawi, Hatoon Ajwad al-Fassi and Abeer Adbdullatif Al Namankany.

The Guardian has been told the examinations took place in January and the medical reports, which are marked confidential, have been included in a detailed overview that includes three broad recommendations to the king about what to do next.

According to the medical reports seen by the Guardian, the comments about the detainees suggest many have been severely ill-treated and have a range of health problems.

In almost all cases, the reports demanded the prisoners be urgently transferred from solitary confinement to a medical centre.

Crown Prince Mohammed bin Salman, left, with King Salman.

The remarks on detainees include:

“The patient suffers from severe weight loss with continuous bloody vomiting. There are also a number of wounds and bruises scattered in several areas of the body”

“There are also a number of visible injuries in the chest and lower back”

“The patient must be transferred from solitary confinement to the specialised clinic for immediate treatment and further medical examinations”

“The patient has difficulty walking because of a number of bruises visible on the legs area. A number of injuries are also visible on the forearm and lower back area. Malnutrition and obvious dryness on the skin”

“The patient suffers from a number of bruises visible on the body, especially in the areas of back, abdomen and thighs. It also appears to be malnourished due to lack of eating and facial pallor and general weakness in the body”

“The patient cannot move at all due to wounds in both legs as well as severe weakness in the body due to malnutrition and lack of fluids”

“The patient suffers from severe burns throughout the body. Old wounds were not completely healed because of medical negligence”

“The patient suffers from difficulty in movement due to severe malnutrition and general lack of fluids. There are also a number of bruises, wounds and sores throughout the body”

The recommendations from some advisers to the king include a pardon for all political prisoners, the release of individuals jailed from 2017, and the release of prisoners deemed to have health problems.

On Thursday, Saudi Arabia released pending a full trial three women, believed to be Aziza al-Youssef, Eman Al Nafjan, and Dr Rokaya Mohareb.

The Guardian approached Saudi authorities on 21 March for comment. A spokesman said he would respond, but has not provided a comment.

In previous media reports, a spokesman for the Saudi embassy in Washington said the kingdom had signed the convention against torture and prohibits its use. He said Saudi Arabia “takes any and all allegations of ill treatment of defendants awaiting trial or prisoners serving their sentences very seriously”.

The Guardian was warned by several human rights experts during the course of its reporting that trying to contact family members of people in detention would pose serious risks to the family members living in Saudi Arabia. Rights organisations and activists who track detentions confirmed the nine individuals named in the medical reports were in custody in January.

The reasons for their arrests vary, and in some cases, their alleged offences have not been published.

Human Rights Watch called for Saudi Arabia to “immediately release all jailed human rights activists and peaceful dissidents, and invite international monitors to conduct a comprehensive and transparent investigation into their treatment”.

A spokesperson added: “Saudi detainees including women activists have alleged that authorities mistreated them with unspeakable cruelty, including electric shocks, whippings and sexual harassment, and new revelations of medical reports appear to confirm what they have said for months.”

One rights activist, who spoke on the condition of anonymity, said the descriptions contained in the reports, including that individuals were being held in solitary confinement, were consistent with evidence that had been collected by activists.

A protester’s picture of the Saudi journalist Jamal Khashoggi, killed while visiting the Saudi consulate in Istanbul. Photograph: Osman Örsal/Reuters

The person said the only way to verify the reports fully would be to give independent monitors access to the individuals who had been identified, and make their assessments public.

The activist said female prisoners had been electrocuted, tied to chairs and beaten around their thighs, backs and buttocks with an agal, a cord that men use to keep their headdresses in place.

The lashes led to deep and lasting bruising. Female prisoners have also been described as experiencing severe weight loss, with one woman said to have lost half her body weight, according to the activist.

Justin Shilad, a Middle East research associate at the Committee to Protect Journalists, said the case of Fahd al-Sunaidi, a journalist, showed the extent and reach of the crackdown ordered by the crown prince.

“This is not someone who really stirred the pot in terms of the topics he covered … The fact that he is in detention for no discernible reason, the fact that he was not known as a controversial figure, it really demonstrates the totality of Mohammed bin Salman’s crackdown on press freedom, on independent journalism or any commentary that smacks of a critical or independent nature,” he said.

“In terms of researching Saudi Arabia [and political detentions], the cone of silence is not like anything I have ever seen, and I have researched Libya, Syria, Yemen, Iraq … The level of fear, intimidation and all round silencing of information, it is beyond what we see in the war zones in the region where you have the Islamic State operating.”