The ONE Campaign is an anti-corruption charity fronted by U2 lead singer Bono. In an ironic turn of events, the organization is currently under fire over bullying of staff members in its Johannesburg offices.

According to an investigation by the Mail Online, four employees threatened to take legal action against the organization over ill treatment. They claimed they were "treated worse than dogs" and were ridiculed and belittled in front of staff and in public.

The investigation revealed several cases of toxic behavior in the office.

One former manager was quoted by the Mail Online as saying:

"The toxic environment was terrible, with staff treated so badly. It was awful for an organization that claims to fight for social justice, respect and equality. I had never seen anything like this. This went on for years. It would never have been allowed to happen in London or Washington but we were just Africans. Their attitude was let them eat themselves. When a delegation was sent from London to dampen the disquiet, they told staff to rub a wooden elephant to channel 'negative energies'."

Most of the mistreatment has been attributed to the charity's former executive director Sipho Moyo. She is accused of:

• Demoting a married, female staff member after she refused to sleep with a Tanzanian MP
• Inviting staff to parties at her house, only to use them as waiters and waitresses
• Pressuring a worker to give her a foot massage

She denied all these accusations but admitted the charity wasn't paying taxes on employees' salaries, which she says is a decision that was taken in Washington DC.

Bono has since publicly apologized, saying:

"We are all deeply sorry. I hate bullying, can't stand it. The poorest people in the poorest places being bullied by their circumstance is the reason we set up ONE. So to discover last November that there were serious and multiple allegations of bullying in our office in Johannesburg left me and the ONE board reeling and furious. You question the whole reason you're doing this."

He admitted he was aware of the concerns and was under the impression they were being dealt with.

"My team and I heard concerns about low morale and poor management in this office but nothing along the lines of what emerged recently. I was assured that those concerns were being dealt with – clearly, they were not."

He also promised to meet the victims in person and apologize personally.

So much for a guy who wants to solve Africa's problems.