Rachael Denhollander, the former US gymnast who was the first to bring accusations of abuse against the disgraced Larry Nassar, has hit back at Sovereign Grace Church (SGC) after the evangelical outfit denied allegations of abuse cover-up.

Denhollander's impact statement in court was the last of more than 150 survivors and went viral among America's Christian community. 'I pray you experience the soul-crushing weight of guilt so you may someday experience true repentance and true forgiveness from God, which you need far more than forgiveness from me – though I extend that to you as well,' she said.

But she also said that speaking out for sexual abuse victims had 'cost me my church and our closest friends'. Later she clarified that remark was directed at Sovereign Grace Ministries (SGM), now Sovereign Grace Church (SGC), describing it 'one of the worst, if not the worst, instances of evangelical cover-up of sexual abuse' in an interview with Christianity Today.

SGC hit back and said her claims were 'mistaken' and 'are not true and have never been true'. SGC executive director Mark Prater said in a statement on the church's website: 'We thank God for Rachael's courage in confronting Nassar and commend her invaluable work on behalf of other abuse victims. Like so many, we were impressed by her faithful witness to Christ in such difficult circumstances.

'At the same time, it needs to be said that she is mistaken in her accusations made against Sovereign Grace Churches and CJ Mahaney.

He added: 'It's extremely difficult to respond to false accusations without appearing unsympathetic to victims of abuse. It is our sincere hope that this brief statement has done both by speaking truthfully, respectfully, and in a way that honors God.'

But Denhollander is refusing to back down as a controversy dating back to 2012 over the controversial CJ Mahaney is reignited.

'I am glad to know that SGC is concerned about victims of sexual assault, but I assure them the most unsympathetic thing they can continue to do is refuse to respond to the concerns of sexual assault victims, myself included,' she wrote on her Facebook page. 'I have no need to be protected from any evidence or response they have. On the contrary, I have sought out this evidence and a response, for more than seven years.

'I chose to pursue expertise in the area of sexual assault and institutional dynamics years ago, including my own legal training as an attorney. Having reviewed the allegations and evidence against SGM and their own responses to it, my concerns have only solidified and grown.'

She urged the network to allow GRACE (Godly Response to Abuse in the Christian Environment) to conduct an independent investigation.

The dispute centres around allegations that the SGC network covered up abuse. SGC denied the claims.