A group of international researchers have reported success in growing lab-made mouse sperm and claim their breakthrough could one day help infertile men father children without using a sperm donor.

The scientists were able to grow viable sperm in a laboratory dish using just a few mouse germ cells, which are found in testicles and are responsible for sperm production. The researchers said the sperm, which appeared healthy and free of genetic abnormalities, could have been used to create baby mice.

Led by Professor Stefan Schlatt from Germany's Munster University, the team was hopeful their technique could one day be applied to humans.

"I believe it will eventually be possible to routinely grow human male sperm to order by extracting tissue containing germ cells from a man's testicle and stimulating sperm production in the laboratory," said Mahmoud Huleihel, an Israeli researcher on the team, in a statement.

"It has taken us several years to reach this stage so a technique to create human sperm won't come overnight but we have started that research already after our success with mice," he added, according to The (London) Daily Telegraph.

The study, which is being published in the Asian Journal of Andrology, comes months after a group of Japanese scientists claimed to be the first to transform mouse embryonic cells into sperm, which was then used to fertilize mouse eggs and produce healthy and fertile offspring.

The recent breakthroughs follow years of attempts to make sperm and eggs in a dish.

Scientists in 2003 proved it was possible to turn mouse embryonic stem cells into both sperm and eggs, but could not use those cells to bring about successful pregnancies. A few years later, lab-made sperm was successfully used to produce several mice, but the animals all had genetic defects and died early.

Read more at the Telegraph.