What's wrong with cloning humans?

It was one of those mornings when you wake up, smile at the blue sky, flick through the papers, and gently sink your head into your hands and weep.

Here's what happened. Yesterday afternoon, a London PR firm called Markettiers4dc sent the Guardian a press release promoting a documentary due to air on the Discovery Channel tonight.

The programme being touted is called Human Cloning. In it, the press release gushed, we'd go behind the scenes with "the hugely controversial fertility scientist, Dr Panayiotis Zavos, throughout his continuing attempts to create the first cloned human being."

The release goes on:

Reporter Peter Williams MBE – who thirty years ago made a film about the world's first test-tube baby – was given unrestricted access to Dr Zavos' work. The last time Zavos was in London in January 2004, he outraged the medical establishment by announcing that he had already transferred a cloned human embryo into the womb of an unnamed surrogate.

Later in the release, we're told how Zavos has been forced to continue his work in a secret lab in the Middle East. That's mostly because what he's trying to do is – in many countries – considered unethical, illegal or both.

Zavos has, the release continued, implanted 11 cloned embryos into four women, though none has gone on to produce a live birth. We're not told what did happen to them.

This is familiar publicity-grabbing territory for Dr Zavos. In 2001, he teamed up with the controversial Italian embryologist Severino Antinori to announce they had 10 women lined up who wanted to have cloned embryos implanted. The two parted in acrimony some time later.

In 2004, Zavos said he had implanted a cloned embryo into a 35-year-old woman, so she could give birth to a clone of her husband. Because Zavos gave no details and had not published the work, many scientists dismissed him as a charlatan.

Some of Zavos's patients have reportedly been told that treatment would cost the same as IVF, only for the figure to rise to nearly £50,000 later on.

Zavos re-appeared in 2006, when he told the Guardian he had transferred cloned embryos to five women, including one 52-year-old Briton.

This kind of history makes enormous alarm bells clang whenever you see the person's name again. And so back to that press release. I sent a note back to the PR agency saying I needed a lot more information to judge whether or not Zavos had really created cloned embryos.

I got a reply from the agency saying they would try and get some more credible evidence for the claims. None arrived. This morning they sent me a video clip of some embryos filmed down a microscope. It's impossible to tell if they are cloned embryos.

The Independent decided to splash the story on its front page this morning, and it will very probably help shift a few newspapers.

I don't think it was wrong to cover the story. It's interesting. What I despair of is that the tale that emerged is purest, spoonfed PR. The Discovery Channel can't be faulted for wanting publicity for its programme, but for the media to play along and present it as credible and factual without anything approaching sound evidence is disappointing. It's galling too that I'm only succeeding in giving it more attention now.

The media's part in this is a sideshow of course. The real issue is that reproductive human cloning is not remotely safe with today's technology. For this reason, it is illegal in the UK. A cloned baby is likely to be miscarried, or be stillborn, or delivered with significant birth defects.

When the technology behind test tube babies was introduced in the 1970s, research in animals had already shown the technique was safe. Conversely, almost every attempt to clone a new animal species has been marred with birth defects or worse. To try and clone humans with today's rudimentary expertise is reckless.

In the documentary, Zavos claims to have created cloned embryos of three dead people, including a 10-year-old girl called Cady who died in a car crash. The mother has, we are told, expressed an interest in having the child cloned.

This is another car crash in the making, albeit a psychological one. A cloned baby – if it survives – will be a very different person to whoever donated the cells from which it was created. Bringing a child up expecting it to be someone it is not is a sure-fire disaster. It will look similar, but it won't behave the same way, despite its parents' expectations.

We'll no doubt be hearing more from Zavos in the future. One thing I would like to see from him are the records of his failures. What happens to the embryos that are transferred? How many fail to implant? How many are miscarried later on? If any grow into foetuses, what abnormalities do they have?

If human cloning were safe, the arguments against using the technology in reproductive medicine would change rapidly and dramatically. Attempting it with today's imperfect technology is simply exploiting those vulnerable and desperate enough to pay for it.