Sarah Depoian (right) is suing Dr Merle Berger for using his sperm to impregnate her with her daughter Carolyn Bester (left) (Picture: Sarah Depoian via AP)

The founder of one the largest fertility clinics who helped thousands of families have children has been accused of secretly impregnating a patient.

Dr Merle Berger told patient Sarah Depoian, now 73, the sperm would come from an anonymous donor ‘who resembled her husband, who did not know her, and whom she did not know’ in 1980, according to a lawsuit.

He performed an artificial insemination which resulted in Depoian’s daughter, Carolyn Bester, being born the following year.

But Ms Bester found out Berger was her biological father after conducting a home DNA test earlier this year, according to a lawsuit.

Adam Wolf, a lawyer representing Depoian, said Berger clearly knew that what he was doing was wrong.

‘Some people call this horrific act medical rape, but regardless of what you call it, Dr. Berger’s heinous and intentional misconduct is unethical, unacceptable and unlawful,’ Mr Wolf said.

Ms Bester, 42, said she received DNA results from Ancestry.com and 23andMe as she explored her history earlier this year.

The results didn’t show a direct match to Berger but identified a granddaughter and second cousin of his.

She spoke to one of the relatives and started to piece together the puzzle.

‘To say I was shocked when I figured this out would be an extreme understatement. It feels like reality has shifted,’ said Ms Bester, who lives in New Jersey.

‘My mum put her trust in Dr. Berger as a medical professional during one of the most vulnerable times in her life. He had all the power and she had none.’

In the lawsuit, Ms Depoian is seeking ‘damages in an amount sufficient to compensate her for her injuries’.

‘We fully trusted Dr. Berger. He was a medical professional. It’s hard to imagine not trusting your own doctor,’ said Ms Depoian, who lives in Maine.

‘We never dreamt he would abuse his position of trust and perpetrate this extreme violation. I am struggling to process it.’

Ian Pinta, a lawyer representing Berger, described him as a pioneer in the medical fertility field.

He described him as a pioneer in the medical fertility field who helped thousands of families fulfill their dreams of having a child.

‘The allegations concern events from over 40 years ago, in the early days of artificial insemination,’ Pinta said in a written statement.

‘The allegations, which have changed repeatedly in the six months since the plaintiff’s attorney first contacted Dr. Berger, have no legal or factual merit, and will be disproven in court.’

A spokesperson for Boston IVF Fertility Clinic, which Berger helped found, said the situation cited in the lawsuit occurred before Berger’s employment at the clinic and before the company even existed.