The researchers said they had already produced early sperm cells from bone-marrow tissue taken from men. They believe the findings show that it may be possible to restore fertility to men who cannot naturally produce their own sperm.
But the results also raise the prospect of being able to take bone-marrow tissue from women and coaxing the stem cells within the female tissue to develop into sperm cells, said Professor Karim Nayernia of the University of Newcastle upon Tyne.
Creating sperm from women would mean they would only be able to produce daughters because the Y chromosome of male sperm would still be needed to produce sons. The latest research brings the prospect of female-only conception a step closer.
"Theoretically is it possible," Professor Nayernia said. "The problem is whether the sperm cells are functional or not. I don't think there is an ethical barrier, so long as it's safe. We are in the process of applying for ethical approval. We are preparing now to apply to use the existing bone marrow stem cell bank here in Newcastle. We need permission from the patient who supplied the bone marrow, the ethics committee and the hospital itself."
If sperm cells can be developed from female bone-marrow tissue they will be matured in the laboratory and tested for their ability to penetrate the outer "shell" of a hamster's egg - a standard fertility test for sperm.
"We want to test the functionality of any male and female sperm that is made by this way," Professor Nayernia said. But he said there was no intention at this stage to produce female sperm that would be used to fertilise a human egg, a move that would require the approval of the Human Fertilisation and Embryology Authority.
The immediate aim is to see if female bone marrow can be lured into developing into the stem cells that can make sperm cells. The ultimate aim is to discover if these secondary stem cells can then be made into other useful tissues of the body, he said.
The latest findings, published in the journal Reproduction: Gamete Biology, show that male bone marrow can be used to make the early "spermatagonial" stem cells that normally mature into fully developed sperm cells.
"Our next goal is to see if we can get the spermatagonial stem cells to progress to mature sperm in the laboratory and this should take around three to five years of experiments," Professor Nayernia said.
Last year, Professor Nayernia led scientists at the University of Gottingen in Germany who became the first to produce viable artificial sperm from mouse embryonic stem cells, which were used to produce seven live offspring.
His latest work on stem cells derived from human bone marrow suggests that it could be possible to develop the techniques to help men who cannot produce their own sperm naturally.
"We're very excited about this discovery, particularly as our earlier work in mice suggests that we could develop this work even further," Professor Nayernia said.
Whether the scientists will ever be able to develop the techniques to help real patients - male or female - will depend on future legislation that the Government is preparing as a replacement to the existing Human Fertilisation and Embryology Act.
A White Paper on genetics suggested that artificial gametes produced from the ordinary "somatic" tissue of the body may be banned from being used to fertilise human eggs by in vitro fertilisation.
Making babies without men - a literary view
Aristophanes (c. 411BC)
After 21 years of war, the women of Athens, led by Lysistrata, take matters into their own hands. Lysistrata suggests every wife and mistress should refuse all sexual favours until peacetime. Before long it proves effective, peace is concluded and the play ends with festivities.
Charlotte Perkins Gilman (1914)
On the eve of the First World War, an isolated society entirely comprising Aryan women is discovered by three male explorers. The women reproduce asexually and live in an ideal society without war and domination. This feminist utopia is a 20th-century vehicle for Gilman's then-unconventional views of male and female behaviour, motherhood, individuality, and sexuality. It is said to be based on Gilman's version of utopia through Aryan separatism.
Philip Wylie (1978)
At four minutes and 52 seconds past four one afternoon, the world shatters into two parallel universes as men vanish from women and women from men. With families and loved ones separated from one another, life continues very differently as an explosion of violence sweeps one world while stability and peace break down in the other.
Doris Lessing (2007)
In her novel, which has made this year's International Man Booker shortlist, Lessing portrays a group of near-amphibious women who have no need of men, known as Squirts, as they are impregnated by the wind, wave or moon. But this is no feminist utopia: the women behave brutally, mutilating male babies before placing them on a rock for eagles to devour. The eagles turn out to be the men's allies, transporting the babies to the forest where they are suckled by does. Lessing reveals she was inspired by a scientific claim that "the primal human stock was probably female, and that males came along later, as a kind of cosmic afterthought".