Zuriah Namutamba still has questions about how her grandson died. About whether the actions of a young American woman, a missionary without any medical training, contributed to Twalali Kifabi’s death.

Zuriah is not the only relative in Uganda demanding answers over the work of the US missionary organisation Serving His Children (SHC) and its founder, Renee Bach, who has now left the country.

Families of other children who died subsequently seeking help from SHC – at least 105 other cases over several years – are also seeking accountability in a court case to be decided next year. It is alleged that Bach, 30, involved herself in medical interventions with children, including blood transfusions, despite having no qualifications either as a doctor or a nurse.

Amid growing unease about the behaviour of so-called “white saviours” in Africa – often unqualified evangelicals working for small missionary outfits – the long-running allegations against Bach and SHC have taken the issue to a whole new level of seriousness.

The case being played out in Uganda, and in the international media, has presented starkly contradictory accounts of what occurred at SHC on Bach’s watch.

Founded in Uganda in 2009 by Bach “to promote evangelism, provide welfare for the needy and empower families”, SHC was registered in the country as an NGO two years later.

On its website, the group describes itself in grandiose terms as a “God-breathed and directed ministry working to end malnutrition in families and communities” that “partner[s] with the government of Uganda to provide inpatient therapeutic care for children suffering from severe acute malnutrition”.

But critics of SHC and Bach paint a different picture – not least in its early years – of an amateur and enthusiastic group whose staff, including Bach, sometimes participated in medical treatment for which they were not qualified.

It is a depiction that SHC and Bach’s lawyer, David Gibbs, have pushed back against in the strongest terms, defending their work and describing accusers in Uganda of being “reputational terrorists” spreading “false information”. They have suggested in court papers that some of those making allegations were former and disgruntled employees and associates with axes to grind.

According to Zuriah, SHC, then based in the eastern Ugandan town of Jinja and run by Bach, seemed at first a world apart from the local health centres.

Caretakers and patients received free food, and Bach herself came across as warm, engaged and compassionate, offering hugs and comforting the mothers whose children were sick.

“We thought she loved us. She would hug you to calm you down. She told us our children would be well,” Zuriah recounted to the Guardian.

Zuriah says she knew Bach well enough by sight to be able to be certain of identifying her, adding that she took her grandson to SHC when he fell ill. She insists she saw Bach administer medicine to Twalali and place him on oxygen.

Bach’s lawyers say that is impossible, claiming she was out of the country when Twalali was treated. They have provided passport pages to the court as evidence.

Other witnesses in Uganda have told similar stories to media outlets, including the Guardian.

Mothers of children who died at SHC – including Twalali’s mother, Zubeda Gimbo – claim in a court case, filed earlier this year in Jinja, that they were led to believe Bach was a trained doctor. Bach emphatically denies she ever sought to give that impression.

One focus of contention has been a series of photographs depicting Bach in situations with a medical care context.

Another issue has been claims that Bach herself carried out interventions, including administering IV drips into veins. On this there is less argument.

Bach has admitted sometimes inserting drips, claiming that she had been trained how to do this by a health professional on a “wilderness first aid course”.

In a statement, SHC deny Bach passed herself off as a doctor, but admit she regularly helped in “crisis situations” using “skills” learned from Ugandan healthcare professionals.

“As Ms Bach worked along[side] Ugandan medical professionals, she learned skills to help provide assistance as necessary; and she often assisted nurses and other healthcare professionals to serve in crisis situations. She never represented herself as a doctor or nurse, but she made nutritional care provided by qualified medical professionals more accessible for families in rural areas,” said the statement.

It is not only those involved in the case making accusations. Grace Adikin, 35, said she became concerned about the circumstances of her two-year-old child’s death after the allegations about SHC emerged.

She was referred to SHC by a friend in 2014. When she reached the mission, she said, the infant was quickly taken away from her by a woman she identified as Renee Bach herself.

Three hours later, when the child was brought back to her, she could see a cannula had been inserted. She alleges that she was told a blood transfusion had been necessary.

The infant was then taken to a children’s hospital but died shortly after arrival.

“Renee put us in her car and drove us to a nearby Nalufenya children’s hospital,” Adikin said. With all the allegations about Renee’s work now, I have also become suspicious,” she said.

“They did a blood transfusion without telling us what the child was suffering from.”

Despite three approaches from the Guardian, which contacted both Bach’s lawyer and SHC, the NGO did not engage with specific questions. They instead replied with a press release issued in June – despite having put Bach forward for TV interviews in the US.

In responses to the allegations over recent months, SHC and Bach’s lawyer have insisted that the lawsuit filed against Bach by two mothers is “entirely without merit”, insisting that one of the children named in the lawsuit was never treated by SHC, while the other child was treated there while “Bach was not in Uganda”.

In the release, the organisation defended its work, suggesting that media reporting had put Bach and SHC at risk.

“For the last 10 years, Renee Bach and Serving His Children have served malnourished children in Uganda. Reputational terrorists are attacking Renee Bach and Serving His Children with false allegations using the platform of social media to create a false reality without factual evidence.

“These escalating attacks are currently threatening the personal safety of Ms Bach and her family, as people are believing these lies about her and the services provided by the organisation. Several media outlets are escalating these safety risks by globally sharing grossly false information.”

The press release quoted Gibbs: “It is sad when people spend their time attacking the good work of others. Renee is innocent of the nonsensical allegations being levelled at her by people who are leveraging the power of social media for their own agenda without verification of facts.”

Despite the denials, Primah Kwagala, the executive director of Women’s Pro-bono Initiative, the Ugandan organisation representing the women, said she was anxious to see Bach in court in Uganda, primarily to underline the message that organisations such as SHC cannot come to the country and operate without proper checks and balances.

“I want Renee to know that she did something wrong and she needs to be held accountable,” said Kwagala. “It is for people to know that if they do what Renee has done, including Ugandans, they will have to pay.”