As a married father-of-four who until last year was earning a lucrative living as a head-hunter in the City, John Gonzalez is an unlikely crusader for lesbian rights.

But the success of his latest business venture has earned him both a substantial profit and widespread praise from the lesbian community.

Gonzalez is the founder of mannotincluded.com, the website that hit the news last week after the birth of the first baby in Britain to be conceived from sperm purchased on the internet.

The response of family campaigners, religious groups and ethical medical watchdogs has been furious; Gonzalez was accused of putting the mothers and babies at risk of diseases including HIV, ignoring the rights of children and undermining the building blocks of society.

But far from being horrified by the response, the 41-year-old Roman Catholic was last week glowing in the heat of the furore. 'I love and relish a fight,' he said. 'If someone, somewhere gives me a problem about what I'm doing, it means I'm doing something worth confronting.'

Gonzalez claims that 19 other women are more than six months pregnant after using the service, although the new parents were the only heterosexual couple on his books.

But if he seems unsuited to the role of gay rights hero, Gonzalez appears even less likely to be a moral anti-hero: having had to leave home for a 7am meeting the morning of his interview with The Observer, he had found time to gel his hair into a mass of carefully dishevelled spikes but cheerfully admitted to forgetting to put on his socks.

'People think I'm a bit sharp and that I'm flying by the seat of my pants,' he said, his oversized shirt flapping loose at the cuffs. 'But I love people to have that perception, because the reality is that every time I open my mouth I've thought about what I'm going to say and what effect it's going to have.'

Gonzalez stumbled on the idea of setting up a home insemination service last year after discovering that most fertility clinics refuse to treat lesbian couples.

'I was looking at gay websites for another project when I realised how many adverts there were from lesbians asking for sperm donors,' he said. These women, he realised, were being forced to advertise to complete strangers or come to private arrangements with friends prepared to donate sperm.

It was a happy accident that in one year the project has made him extremely wealthy: more than 5,000 women have paid the £830 fee to register with the website, about 60 of whom each month decide to go ahead with the service. More than 800 men are listed as donors, receiving up to £80 a month for their services.

'Financially this business is a good thing for me, and I'm not going to deny it,' he said from his offices in the Woman's New Life Centre in Harley Street. 'But I'm also massively motivated by the injustice of women who are being denied a basic human right and the fact that denial forces them into highly dangerous situations.

'The dangers that women attempting to arrange home insemination put themselves through are terrifying,' he said. 'Most women don't have the first idea what to test their would-be donors for, leaving them at risk of diseases such as chlamydia, which can cause miscarriage and infertility.

'But there's also the question of what the real motivations are of the donors who reply to such adverts. Any one of my daughters could be in the position as one of my clients in 20 years' time. Do I want them to advertise for a sperm donor? Absolutely not.'

Mannotincluded.com effectively operates as a for-profit sperm bank, acting as an introduction agency between male donors and would-be recipients, providing medical screening and arranging for the delivery of fresh sperm along with a home insemination kit.

Critics have raised concerns that, because it deals in fresh and not frozen sperm, the Woman's New Life Centre remains unlicensed by the Human Fertilisation and Embryology Authority (HFEA). They also point out that fresh sperm cannot be subjected to tests for diseases with incubation periods such as HIV.

But Gonzalez is adamant the sperm his organisation offers is safe, pointing out that donors are screened before they are allowed to donate and continue to be tested every eight to ten weeks.

'We would say our is just as safe as frozen sperm; it's as safe as is humanly possible,' he said. But the lack of supervision has also sparked concern and accusations that Gonzalez is willing to deliver sperm to anyone who has the money to pay.

'Contrary to popular belief, we do have parameters,' he said. 'We make sure that what we do has a modicum of ethics behind it; we wouldn't let a white couple adopt a Chinese baby, for example, and there are moral dilemmas: if a couple where one person was white and one mixed-race wanted a non-white baby. We do use counsellors in order to get to the bottom of situations like that.'

Gonzalez submits would-be recipients to a counselling session before agreeing to supply them with sperm, but admits he is ambivalent about its use. 'I think you can over-counsel sometimes. If you've spent the last three years thinking about having a child, is it really going to be useful to talk to a third person?

'Do we take advice of our counsellors? We would take what they say and make it part of the process of doing what we do,' he said. 'But I think you instinctively know when something is not right, like when people say they just want to send us money and have the sperm sent straight out without any other contact with us. That, for me, sets alarm bells ringing.'

Gonzalez does admit that not all of his staff are trained, but he defends his decision. 'Training is overvalued: if you see some of the people working in licensed fertility clinics, you'd be shocked at the way they treat women,' he said. 'If that's what being trained is, I would rather have a bunch of monkeys working for me who have a modicum of sympathy.'

Once this furore has settled down, Gonzalez has other plans; he is on the cusp of acquiring two more clinics - licensed this time - in the UK and opening five more across Europe. 'There are many more fights in the pipeline,' he said happily. 'It's going to be fun.'