Oxfam failed to act on reports children were being sexually abused by its workers in Haiti in 2011, according to a major Charity Commission inquiry which concluded the allegations were “not taken seriously enough”.

A report by the Charity Commission into Oxfam GB, undertaken in response to revelations last year of sexual exploitation by its aid workers, concludes the safety of potential victims took “second place”.

It discloses a series of emails received by the NGO in 2011 alleging some workers were having sex with women and girls, including minors, in refugee camps after their homes were destroyed by the earthquake which devastated the country in 2010.

Oxfam suspected the emails were not genuine, and did not raise them with local police.

In one case, two emails dated 18 July 2011 and 20 August 2011 – both said to be from a 13-year-old Haitian girl – alleged she and a 12-year-old friend had suffered physical abuse and other misconduct at the hands of Oxfam staff.

World mobilises to provide Haiti aid Show all 22 1 /22 World mobilises to provide Haiti aid World mobilises to provide Haiti aid A injured child receives medical treatment after an earthquake in Port-au-Prince January 13, 2010. The 7.0 magnitude quake rocked Haiti, killing possibly thousands of people as it toppled the presidential palace and hillside shanties alike and leaving the poor Caribbean nation appealing for international help. Reuters World mobilises to provide Haiti aid A student assists the wounded, following a major earthquake on January 13, 2010 in Port-au-Prince, Haiti. Getty Images World mobilises to provide Haiti aid An injured girl waits for medical attention after an earthquake in Port-au-Prince. Reuters World mobilises to provide Haiti aid Resident search for survivors among the debris after an earthquake in Port-au-Prince. Reuters World mobilises to provide Haiti aid A view of the Canape-Vert area after an earthquake in Port-au-Prince January 13, 2010. A major earthquake rocked Haiti and its president said he feared thousands were dead after the presidential palace, schools, hospitals and hillside shanties collapsed. Reuters World mobilises to provide Haiti aid Displaced people gather on Place Boyer in Petion-Ville to spend the night, following a major earthquake on January 13, 2010 in Port-au-Prince, Haiti. Getty Images World mobilises to provide Haiti aid A man walks in front of Haiti's Presidential Palace which was destroyed after a major earthquake struck, in Port-au-Prince Reuters TV World mobilises to provide Haiti aid People are seen near the ruins of a building destroyed after a major earthquake struck in Port-au-Prince Reuters TV World mobilises to provide Haiti aid Damage to a building is seen on January 12, 2010 in Port-au-Prince after a huge quake measuring 7.0 rocked the impoverished Caribbean nation of Haiti Clarens Renois/AFP/Getty Images World mobilises to provide Haiti aid An injured man carries his dead daughter after an earthquake devastated Port-au-Prince, Haiti. Reuters World mobilises to provide Haiti aid People help a casualty after a major earthquake struck, in Port-au-Prince Reuters TV World mobilises to provide Haiti aid A fire breaks out near a building, which was damaged after a major earthquake struck, in Port-au-Prince Reuters TV World mobilises to provide Haiti aid People react as a girl collapses on a street after a major earthquake struck, in Port-au-Prince Reuters TV / Reuters World mobilises to provide Haiti aid A fire breaks out after a major earthquake struck, in Port-au-Prince Reuters TV World mobilises to provide Haiti aid People walk along a street lined with buildings destroyed after a major earthquake struck in Port-au-Prince Reuters TV World mobilises to provide Haiti aid A man stands in front the police headquarters which was damaged after a major earthquake struck, in Port-au-Prince Reuters TV World mobilises to provide Haiti aid A man calls for help while being trapped at the Port-au-Prince University, after a major earthquake struck, in Port-au-Prince last night. Reuters World mobilises to provide Haiti aid A woman is trapped at the Port-au-Prince University, after a major earthquake struck in Haiti last night. Reuters World mobilises to provide Haiti aid People react on a street after a major earthquake struck in Haiti's capital last night. Reuters World mobilises to provide Haiti aid A injured resident waits for medical attention after an earthquake in Port-au-Prince January 13, 2010. The 7.0 magnitude quake rocked Haiti, killing possibly thousands of people as it toppled the presidential palace and hillside shanties alike and leaving the poor Caribbean nation appealing for international help. Reuter World mobilises to provide Haiti aid Residents search for victims after an earthquake in Port-au-Prince January 13, 2010. The 7.0 magnitude quake rocked Haiti, killing possibly thousands of people as it toppled the presidential palace and hillside shanties alike and leaving the poor Caribbean nation appealing for international help. Reuters World mobilises to provide Haiti aid A resident waits for medical treatment after an earthquake in Port-au-Prince January 13, 2010. The 7.0 magnitude quake rocked Haiti, killing possibly thousands of people as it toppled the presidential palace and hillside shanties alike and leaving the poor Caribbean nation appealing for international help. Reuters

The emails stated the girls had been engaging in prostitution and the author had been “beaten and used by two men who I know work for you”. It continued: “They also have a boss who works for you and I have not met, but my young friend. She is 12. Has had sex with him.”

The inquiry established that the emails were not raised with any law enforcement at the time and former trustees said they were not made aware of them.

Taking into consideration the “seriousness of the allegations” made in the emails, as well as the “clear risks to the safety and security of those minors” if they were true, the Commission said Oxfam “should have tried harder” and taken more steps at the time to identify the source of the concerns and follow up the allegations.

“Oxfam GB should not have taken the risk with the safety of minors. It should have reported the possibility of two girls being at risk to the local law enforcement authorities … The risk to and impact on the victims appeared to take second place and was not taken seriously enough,” it said.

The Charity Commission said that given the period of time that had passed, it would not be possible to conclude with sufficient certainty whether minors were involved or at risk.

But it raised concerns that Oxfam’s handling of these matters was influenced by a “desire to protection the charity’s reputation and to protect donor and stakeholder relationships”.

Oxfam’s chief executive in 2011 has accepted publicly that further steps could have been taken to determine whether minors were involved in the original allegations.

The findings come nearly a year after it emerged that senior aid workers working for Oxfam had used prostitutes in Haiti. Four members of staff were subsequently dismissed and three, including the country director, resigned.

The report also found that incidents in Haiti in 2011 were “not one-off” and examples of poor conduct by staff and behavioural issues dated back to June 2010.

It said failure to consistently hold people to account for poor behaviour and to ensure robust and consistent action was taken in practice had resulted in a “culture of tolerance of poor behaviour” which “likely resulted in putting victims off speaking up”.

“The risk to, and impact on, the victims appeared to take second place at times and was not taken seriously enough; victims, whistleblowers and those staff who tried to raised concerns were let down,” stated the report.

While the inquiry notes that the NGO has since made “significant progress” in improving weaknesses in its safeguarding, it said “significant further cultural and systematic change” was required to address the issues fully.

In light of the findings, the Charity Commission has exercised its legal powers and issued an official warning to Oxfam on the grounds that there has been some areas of mismanagement in relation to Haiti and its safeguarding governance prior to 2018.

Chair of trustees Caroline Thomson said Oxfam was “deeply sorry for its failure to prevent sexual abuse by its former staff in Haiti” and that it accepted it should have improved its safeguarding “further and faster”.

“What happened in Haiti was shameful and we are deeply sorry. It was a terrible abuse of power, and an affront to the values that Oxfam holds dear,” she said.

“The Commission’s findings are very uncomfortable for Oxfam GB but we accept them. We now know that the 2011 investigation and reporting of what happened in Haiti was flawed; more should have been done to establish whether minors were involved.”

The international development secretary, Rory Stewart, said: “The revelations of last year were horrifying and shone a light on fundamental problems. The Department for International Development [DFID] agrees that we must always put people first.

“DFID has driven reform and our priority remains delivering for the world’s poorest and most vulnerable, while keeping people safe from harm.