A church in South Africa that provides refuge for thousands of homeless Zimbabweans is investigating allegations of child sex abuse.

A teacher at the Central Methodist Church in Johannesburg has been suspended and evicted after being accused of soliciting a girl for sex.

Between 10 and 15 boys and girls without parents have been relocated from the church to shelters around the city, some after allegedly being abused.

Bishop Paul Verryn, head of the inner city church, said he feared the problem was widespread and an internal commission had been set up to examine the claims.

Verryn estimates that 3,000-3,500 people sleep in the church each night, including 110 unaccompanied minors. About 85% are Zimbabweans who have fled the political and economic crisis in their country. They endure cramped conditions and threats such as tuberculosis and violence. Médecins Sans Frontières runs a health clinic next to the church.

Some of the refugees have become teachers at a 525-pupil school set up by the church last year. They earn a salary of R3,500 (£280), funded by a religious organisation in New York and the Dutch government.

But one teacher, a Zimbabwean male, has been suspended and removed from the building, and is due to be interviewed by an internal commission. An anonymous letter sent to Verryn claimed that the man had approached a girl and asked her to be his girlfriend and to sleep with him. The girl rejected his advances, after which he allegedly "made life difficult for her".

South Africa's Eyewitness News television reported that one child said she had been traumatised by her experiences at the church and that many girls there were being abused. She described how girls were being coerced into performing sexual acts for their teachers.

"One of the teachers said 'I'll buy you toiletries'," she was quoted as saying. "A girl in that place ‑ toiletries are gold. He abuses you and then he buys you toiletries."

The girl, who was not named, added: "I just wish people out there could open their eyes and see what's going on and try and help the young girls ‑ the young children ‑ who are in there and try and get them out because that's the most important thing."

Verryn said he took the claims very seriously. "Even the vaguest allegation needs to be examined in the scenario we are in here," he said. "Normally you assume someone is innocent until proven guilty. Here one has to assume guilt until innocence is proved."

He said he would be surprised if it was only one teacher. "I think it's more than one and not just teachers. It's men generally. We are very conscious this issue has to be watched all the time."

Verryn said the problem had been regularly addressed in church. "We've said to the children, 'Your body is sacred. Nobody has the right to touch you if you don't like it. If somebody does interfere with you, don't keep quiet about it.'

"We need to talk about it. One of the good things to come out of this is the exposure, which gives us more chance of beating it."

It was also claimed that children as young as 14 were being recruited to commit crimes. Johannesburg police said they had not received reports of such cases, nor of alleged sexual abuse at the church.