To his patients, he is a god and miracle worker; to his critics, including people who worked with him, he is a dangerous, amoral egotist who is not to be trusted.

At 61, Dr Severino Antinori is younger than some of the women he helps to become mothers long after their natural ability to conceive has stopped. But even as he approaches retirement, Dr Antinori's instinct for controversy - and publicity - has continued unabated.

He was born in 1945 and trained as a gynaecologist before his interest in fertility treatment started in the 1980s when he met the British expert Dr Simon Fishel, part of the team who created Louise Brown, the world's first "test-tube baby".

The two doctors collaborated for years, but the partnership collapsed in the early 1990s, with Dr Fishel saying Dr Antinori had a "terrible temper" and a tendency to see himself as an eccentric genius.

Dr Antinori then set up a clinic in Rome close to the Vatican. Pandering to the needs of wealthy Italian women, he became rich off the back of the increasing demand for fertility treatment but remained relatively unknown until 1993 when other doctors learnt he had helped a 63-year-old Italian women to become pregnant, making her then the world's oldest mother.

The Pope branded him immoral but Dr Antinori, who is a Catholic, insisted: "With the help of God, I help nature. I bring life and joy into the world."

He has since become famous for helping post-menopausal women to become pregnant. Among his "granny-mummies" as they are known, are the 62-year-old wife of an Italian farmer, and a British woman who was 58 when she conceived. Dr Antinori maintains that he makes strict physical and emotional checks on all patients and ensures they have at least 20 years' life expectancy.

Most British fertility experts refuse to treat any woman over 45, although there is no official limit set.

Dr Antinori has continued to court controversy with other stunts, such as promising in the spring of 1999 to create "millennium babies" at £20,000 apiece with a guaranteed (Caesarean) delivery date of 1 January 2000.

Research has shown that, given the right hormones and fertility treatment, women in their 50s and 60s can have the same pregnancy rate as younger patients. What concerns doctors are the hugely increased risks of ectopic pregnancy (when a foetus develops outside the womb) and the complications for mother and child during labour associated with older women.

Even more controversial is Dr Antinori's quest to create a cloned human baby. In 2002 he claimed that a patient was pregnant with the world's first cloned baby but did not produce proof. Two years later, he claimed he knew of three cloned babies but refused to produce any evidence, citing legal reasons. He refuses to allow his work to be peer-reviewed, and the world's top fertility conferences have rejected his submissions to speak because his research is considered unreliable.

Dr Antinori, married and with two grown-up children (his daughter is an embryologist and is being groomed to take over the clinics), revels in his nickname "the father of the impossible children".

And again he has ignited the debate over whether these children should indeed be possible.