Ex boyfriend of Marta del Castillo, the 17 year old girl who has been missing for 21 days from her home in Sevilla, on Saturday confessed to her killing.20 year old Miguel C.D. told police that he had thrown her body into the Guadalquivir River. He had got into an argument with her and hit her with an ashtray until she was dead. He then called a friend of his, named with initials S.B.P. who has now also been arrested, who helped him to throw her body from a quiet pedestrian bridge. A helicopter in the search for the body .He had been missing since her disappearance but was arrested by police on Friday.National Police and Guardia Civil are to restart their search for her body on Sunday in an area between Camas and the Isla de la Cartuja.Marta’s shattered family have made a call for justice, and promised to fight for it. Marta's father Antonio.Her cousin Sandra told the press that the man who has been arrested was Marta’s boyfriend a long time ago, and they went out together for about a month, but had been friends before that. Her uncle in a brief statement to the press called on the media not to refer to her killer as her ex boyfriend, as a relationship of a month is not enough to describe it as such.