IVF guru, a lab scientist and questions over two infants whose mother and father attended his clinic had been secretly fathered by the identical lab technician

Questions were raised about Britain’s most eminent fertility doctor yesterday after it emerged two children whose parents attended his clinic were secretly fathered by the same lab technician.

DNA tests reportedly revealed the two seemingly unrelated adults were both conceived using sperm donated by a senior lab technician who worked one floor above Patrick Steptoe’s fertility clinic at Oldham Hospital.

Dr Steptoe later pioneered in vitro fertilisation (IVF) and the world’s first ‘test tube’ baby, Louise Brown, was conceived in his Oldham clinic in 1978, a historic first that won a Nobel prize and was recently dramatised in the Netflix movie Joy, starring Bill Nighy as the fertility expert.

David Gertler and Roz Snyder, who only discovered they were half-siblings after taking at-home DNA tests, said they believed their mothers were impregnated with the donor sperm without their knowledge or consent, in the early 1970s.

At the time, Dr Steptoe was pioneering a technique to improve the chances of natural conception and Mr Gertler and Mrs Snyder believe their parents did not know that donor sperm was being used at all.

Mr Gertler and Mrs Snyder, who are both in their 50s, grew up in separate families with men they believed were their biological fathers and only discovered they were related earlier this year after taking DNA tests and registering on the genealogy website Ancestry.com.

The results matched them with Roy Hollihead, a scientist who ran a pathology laboratory one floor above Mr Steptoe’s fertility clinic in the 1970s.

Dr Steptoe later pioneered in vitro fertilisation ( IVF ) and the world’s first ‘test tube’ baby, Louise Brown, was conceived in his Oldham clinic in 1978

The historic first won a Nobel prize and was recently dramatised in the Netflix movie Joy, starring Bill Nighy as the fertility expert (pictured)

The retired technician, now 84, told them Dr Steptoe ‘organised a liquid nitrogen sperm bank’ and ‘used sperm from lab staff, medical students and doctors… but no records of any were kept’.

He said he did not know if Oldham’s hospital bosses were aware the senior physician was running the insemination clinic as part of his private practice. Mr Hollihead’s sperm was reportedly used to impregnate at least two other women. One of the resulting children was said to remain unaware of the identity of his biological father, five decades later.

Mrs Snyder, 52, was raised by her father Eddie Kravitz after her mother Doreen died of cancer when she was only 12, and said the discovery of her true biological father was shocking.

She said: ‘I couldn’t speak. It was a shock. My dad is still my dad, but now I know it’s all a lie.’

Historians who documented Dr Steptoe’s work have found no official record of donor insemination carried out at his clinic and paperwork has reportedly been destroyed or gone missing.

Mrs Snyder told The Daily Telegraph that Dr Steptoe’s work on IVF was ‘amazing’, but she added: ‘If he hadn’t done what he had done I wouldn’t be here, my children wouldn’t be here. But it’s how he got there is wrong and the seeming dishonesty surrounding it all.’

Mr Gertler, 51, said he believed his parents were ‘never told’ the truth about his conception. Dr Steptoe died in 1988, shortly before he was to be made a Commander of the Order of the British Empire for his work.

The NHS trust that now runs Oldham Hospital said it had no records of Dr Steptoe’s clinic. A spokesman said: ‘After trying to gain this information, we have no record of this.’