The UN has hired scores of friends and political associates of Syria’s president, Bashar al-Assad, as part of its relief operation in the country, according to documents leaked to the Guardian.

The staff lists show that relatives of high-ranking ministers have been on the Damascus payroll of UN agencies, including the refugee agency UNHCR and the World Health Organisation (WHO).



One former UN manager told the Guardian that every UN agency had at least “one person who is a direct relative of a Syrian official”.

The UN asked the Guardian not to identify any individuals on the staff lists to protect their safety.

A spokesman said “family connections are not taken into consideration nor investigated” when hiring staff, and the UN did not question prospective workers about their political affiliations.



It also denied that the presence of people close to Assad was a threat to the UN’s work and said staff needed to reflect “the fabric of Syrian society”.



In responses, the UN insisted that it remained impartial and defended the need to work with all parties in the conflict.

However, the Syria Campaign, an independent advocacy group, said it was “utterly unconscionable that [a UN] agency dedicated to supporting refugees would employ close relatives of Assad’s inner circle”.



The UN says it has been delivering aid to 13.5 million Syrians in difficult and dangerous circumstances, but accepts that it is constrained by the Syrian government, which only allows the organisation to work with certain Damascus-approved partners.

According to documents seen by the Guardian, almost two-thirds of the emergency health supplies needed in Syria have gone to government-held areas.

They show that 64% of the kits and medicines provided by the WHO since January have been delivered to areas held by or supporting Assad.



Only 13% of WHO supplies have reached Syria’s “besieged” areas, most of which are controlled by forces opposed to the regime.



The UN said its overall response to the crisis was “well-calibrated, balanced and feasible given the security and administrative hurdles we have to work with”.



“In some cases, in some sectors, we are even achieving better reach in non-government-held areas,” a spokesman said.



Stephen O’Brien, the UN undersecretary general for humanitarian affairs and emergency relief, said rebel groups had also prevented medical evacuations from reaching besieged eastern Aleppo during the recent pause in fighting.

Over recent months, the difficulties facing the UN have led to claims from aid groups that it is in hock to the Assad regime, which it denies.

However, concern about this led to 73 aid groups suspending cooperation with the UN’s information sharing system in Syria until there is a transparent inquiry into their concerns that Assad has gained “significant and substantial” influence over the relief effort.

The disclosures come as the diplomatic stalemate continues. Increased Russian pressure on eastern Aleppo has continued, despite a weeklong pause in bombing.

O’Brien addressed the UN security council this week to express renewed anger at the inability of the parties to allow for an easing of the suffering of people in eastern Aleppo.

A halt in the bombing saw pressure on civilians and militants to leave via “humanitarian corridors”, while aid groups focused on trying to secure medical evacuations. But last Saturday, the International Committee of the Red Cross confirmed that no medical evacuations had taken place.



Earlier this month, the British foreign secretary, Boris Johnson, said Russia should be investigated for war crimes and was in danger of becoming a pariah nation for its military support of the Syrian government.



Up to 400,000 people are estimated to have died during the five-year conflict and the situation in Aleppo is so dire that the directorate of health in the east of the city has warned that there are only seven doctors in the area who can perform surgery.



Last month, government-held western Aleppo had 1,415 doctors and 11 public hospitals with 1,383 beds.



The UN has said the continued bombing of eastern Aleppo will destroy the city by Christmas unless there is a ceasefire.

Russian and Syrian forces are determined to remove opposition forces from the area and take back control of the entire city, replicating their policy of evacuations across the country.