In experiments on mice, researchers at the Centre for Reproductive Health at the University of Edinburgh found a gene, called Katnal1, which was vital for the final stages of sperm production.
Detailing their findings in the journal PLos Genetics, the researchers said a drug which interrupts Katnal1 could be a reversible contraceptive.
Contraception in men is largely down to condoms or a vasectomy, but experts said there was "certainly a need" for such a drug, the BBC reported.
The researchers were actually investigating the causes of male infertility, for which they randomly altered the genetic code of mice to see which became infertile.
They then traced the mutations causing infertility, which led them to find Katnal1. It contains the blueprints for a protein which is important in cells that support sperm making. Without the protein, sperm do not fully form and the body disposes of them.
The scientists hoped they would be able to perform a similar trick in humans to stop sperm developing, without causing lasting damage.
Dr Lee Smith, one of the study authors, said: "If we can find a way to target this gene in the testes, we could potentially develop a non-hormonal contraceptive.
"The important thing is that the effects of such a drug would be reversible because Katnal1 only affects sperm cells in the later stages of development, so it would not hinder the early stages of sperm production and the overall ability to produce sperm." (More)
