A revolutionary genetic editing technique designed to repair faulty DNA could be used by criminals to evade justice, experts have said.

The Crispr system acts like molecular scissors to snip away damaged genes and replace them with healthy code and it is hoped it will one day fix genetic diseases such as sickle cell anaemia, cystic fibrosis and muscular dystrophy.

But Professor George Church, of Harvard University, who pioneered the use of the Crispr technique, said it would be possible for criminals to use the technique to disappear from forensic databases or evade detection.

Crispr kits can now be bought online for around £150, and last year former Nasa biochemist Josiah Zayner injected himself with a genetic cocktail during a livestream to increase his muscle mass.

Asked if Crispr could alter DNA to the extent it would make forensic evidence unusable Professor Church told The Telegraph: “We could do that today, easily. A lot of it is done by blood and even if you just get a stem cell transplant you have a new identity.

“I think Crispr actually would be easier than a stem cell transplant because (a transplant) would have to be done sterrily and you would need to irradiate yourself to get rid of the old ones and that is not something even Zayner would do.

“I could imagine there being an industry. My guess is though, they would start with a bone marrow transplant to some random person. You wouldn’t even necessarily need Crispr.”