An Oxfam shop is seen, in London, Britain, 11 February 2018
London – Scandal-hit British charity Oxfam was reeling Tuesday after fresh claims of sexual assault and cover-up in South Sudan, as Haiti&39;s president condemned the behaviour of some of its staff in his country as "undignified and dishonest."
The latest revelations by Helen Evans, former global head of safeguarding, heaped pressure on chief executive Mark Goldring just hours after his deputy resigned over a scandal involving aid workers&39; use of prostitutes in Haiti and Chad.
Evans accused senior managers of failing to act and also warned of assaults on children volunteering in Oxfam&39;s hundreds of charity shops in Britain.
The charity group&39;s name took another hit on Tuesday when Oxfam International&39;s chairman Juan Alberto Fuentes Knight was arrested in his native Guatemala over government graft allegations unrelated to the sexual assault claims.
A spokesman for Oxfam International - the umbrella group for 20 national and regional affiliates - said Fuentes "maintains his innocence" and is cooperating "fully with the investigation."
The sex scandal was slammed Tuesday by Haitian President Jovenel Moisem who said on Twitter that there was "nothing more undignified and dishonest" than humanitarian aid workers exploiting "needy people."
READ: UK threatens charity aid cut-off after Oxfam sex report
Minister of Planning and External Cooperation Aviol Fleurant condemned "serious sexual crimes" carried out by staff members and said they had used money destined for victims of a devastating 2010 earthquake.
Oxfam has been battling accusations it covered up allegations about the use of prostitutes by staff members in Haiti and admitted it could have been more transparent with regulators.
Following an internal investigation, some staff members were dismissed and others including country director Roland van Hauwermeiren were allowed to resign.
The Times newspaper, which broke the story, reported a fellow aid worker made a complaint about van Hauwermeiren over his alleged sexual misconduct back in 2004 while working for the charity Merlin in Liberia.
Minnie Driver quits
Evans told Channel 4 News of a survey conducted during her 2012-2015 tenure which exposed a "culture of sexual abuse" in some Oxfam offices.
The survey of 120 staff across three countries found between 11 and 14 percent said they witnessed or experienced sexual assault. Seven percent of staff in South Sudan -- four people -- witnessed or experienced rape or attempted rape involving colleagues.
The revelations have caused outrage in Britain, where Oxfam received £31,7 million, $43.8 million) from the government last year.
The charity&39;s deputy chief Penny Lawrence resigned on Monday, saying: "As programme director at the time, I am ashamed that this happened on my watch and I take full responsibility."
Actress Minnie Driver became the first Oxfam ambassador to step down from the role late Tuesday
"Devastated for the women who were used by people sent there to help them, devastated by the response of an organisation that I have been raising awareness for since I was nine years old," she wrote on Twitter.
Not first charity
Oxfam is not the first non-governmental organisation to be accused of abuse.
Previous revelations spurred the United Nations in 2002 to issue special measures for all its staff and others, including aid workers under UN contract, based on a policy of zero tolerance.
The issue came to public attention in 2002 after allegations of widespread abuse of refugee and internally displaced women and children by humanitarian workers and peacekeepers in West Africa.
In refugee camps in Guinea, Liberia, and to a lesser extent Sierra Leone, dozens of male aid workers, often locals, were suspected of having exchanged money or gifts for sex with young refugee girls aged between 13 and 18.
"It&39;s difficult to escape the trap of those (NGO) people, they use the food as bait to get you to have sex with them," an adolescent in Liberia was quoted as saying in a report from the UN refugee agency.
More than 40 agencies and organisations and nearly 70 individuals were mentioned in the testimonies taken from 1,500 children and adults for the UN report, which the body stressed could not be verified.
In a 2008 report, NGO Save the Children said "children as young as six are trading sex with aid workers and peacekeepers in exchange for food, money, soap and, in very few cases, luxury items such as mobile phones."
Its findings were based on work with hundreds of youngsters from Ivory Coast, southern Sudan and Haiti.
The report also highlighted instances of rape, verbal sexual abuse, child pornography and prostitution and trafficking of youngsters, many poor, displaced or orphaned by conflict.
The United Nations has also been damaged by a wave of rape cases involving soldiers on peacekeeping missions, ranging from the Central African Republic to Haiti and the Democratic Republic of Congo and Ivory Coast.