Hunting your sperm

Meet Xena. She can track you down through your sperm.

Swedish detectives could soon have a new weapon in their armoury when investigating rapes - a police dog trained to sniff out sperm.

Xena, a five-year-old Belgian Malinois, has spent months being trained for the specialist crime-fighting role.

Her handlers say dogs can be trained to sniff out anything from bodies to bombs, but they have not heard of other forces using dogs in this way before.