Two doppelgangers turned to DNA testing to find out whether they were related.

The 26-year-old women were repeatedly told they looked so alike they could be sisters. But a DNA test proved that the pair weren’t biologically related.

Niamh Geaney and Irene Adams both live in Dublin, Ireland and look strikingly similar. But the test showed that not even the women’s ancestors were related as they hailed from different parts of the globe.

Niamh, a student and television presenter, has set up Twin Strangers, a website which matches strangers who look like each other. Since she started the online project, she has discovered three people who look like her, including Irene.

Describing herself as a doppelganger hunter, Niamh was keen to find out whether her lookalikes were actually related to her by blood. But an ancestry DNA test showed that she was originally descended from South West Asia but Irene’s ancestors came from Mesopotamia.

Comments on social media prompted curiosity

Niamh said: “We both always had this natural curiosity to find out if we were related at all. It was the comments on YouTube and social media that finally made us go for the test, everyone was just so curious and wanted us to prove we weren’t related.”

She added: “Anyone who meets someone who looks identical to them should take a DNA test if they’re curious – I find it fascinating that there could be more to it than just looking the same.

“I think I might try and do another test with my other doppelgängers to see if there’s anything there – we’re supposed to have seven people in the world who look identical to us so my main focus is finding my other four.”

DNA testing can tell you whether you are biologically related to another person. Paternity testing is the most well-known form of DNA testing but tests can also determine whether people are siblings, mother and child or another relative.

Y chromosome testing allows men to find out whether they are related through their paternal line. Ancestry DNA tests, like the one taken by Irene and Niamh, can give you more information about what part of the world you may have originally descended from.