Madrid  - Spanish identical twins who ignored each other's existence met accidentally at the age of 28 years, press reports said Tuesday.

A friend of one of the women saw the other twin at a clothes shop where she worked on Gran Canaria Island in 2001, the daily ABC reported.

She mistook the woman for her friend and wondered why the woman did not greet her.

The incident led to the shop organizing a meeting between the two women, who looked so alike that the saleswoman had a shock.

The women started investigating the circumstances of their births in Las Palmas, and a DNA test later confirmed that one of them had been accidentally exchanged for another baby after birth.

The woman whom one of the twins regarded as her twin sister was the child of another couple which had brought up the real twin.

The discovery upset the twin who had been separated from her parents so much that she needs years of psychiatric treatment, and has sued the maternity hospital for damages worth 3 million euros (4.7 million dollars). (dpa)