The Sofia City Court has decided to keep in detention German Kostin, a Russian citizen suspected of killing a 5-year-old and his mother who lived in Bulgaria.

Magistrates announced the ruling after sitting for nearly seven hours. Kostin will now remain in detention until an investigation is underway.   

Nikita Leontyev, a 5-year-old whose body was found by accident in March in a suitcase near a western Bulgarian village, was killed sometime between February 8 and 10, prosecutors say. His mother was found dead days earlier in an Eastern Bulgarian resort town where she lived with her son.

Last week, a DNA comparison between Kostin and a sample found on a towel in which Nikita's body had been wrapped showed a nearly 100-percent match.

The suspect has consistently denied involvement, claiming "a man from Turkey" who allegedly had a relationship with the mother, Anna, might have been had a role.