Spanish police rescue Colombians kept in slave-like conditions on pig farm
Immigrants worked six days a week while they suffered from diarrhea and vomiting
Spanish police probe witness claims they saw missing teen Diana Quer
Youngster reportedly seen two weeks ago at a bookstore and a restaurant in Lugo province
Mystery surrounds contamination of evidence in Asunta investigation
Semen found on youngster’s clothing was traced to a suspected rapist in Madrid