In a study on mice, human stem cells were grafted onto a tiny ‘scaffold’ which was then implanted under the skin and led to hair growing normally.

The work has been described as a ‘critical breakthrough’ which could help millions of people who suffer from baldness for reasons such as age, genes or illness.

Past tests had trialled a similar method but not been able to control the hair growth, which researchers this time managed to achieve.

A company in the US, Stemson Therapeutics, has already committed to developing the technology which experts hope to move onto testing on people.