The lawsuit, which was filed on 6 January in a US District Court in the Eastern District of Missouri, alleges that the abuse started when she was three and Mr Altman was 12.

In a joint statement on X, with his mother and two brothers, Mr Altman denied the allegations, saying “all of these claims are utterly untrue.”

In the filing, which has been seen by the BBC, Ms Altman alleged that the abuse, which took place over many years, included rape.