Police in the northern Greek city of Serres are investigating the illegal adoption of a baby girl and have identified two people, a retired lawyer and his wife, as key suspects in the alleged crime, authorities said yesterday. The couple are believed to have recently taken part in the attempted sale of an infant in Xanthi to a local couple for 16,000 euros, police said. The suspects could be part of an adoption racket operating out of northern Greece, according to a police source. It was not immediately clear whether the couple are suspected of having taken part in more instances of illegal adoptions. Authorities have identified the biological mother of the infant being sold as a resident of Xanthi. The suspects are expected to be charged today in connection with the case.