Genoa, December 24 - The chief of the Genovese anti-mafia police reported on Monday that significant progress had been made in the investigation into the kidnapping of a businessman in the coastal province of La Spezia seven days ago. "I maintain a cautious optimism," said Michele Di Lecce, head of the Genoa's Anti-Mafia District Directorate (DDA). "Investigators are hearing a number of people right now, some of whom are informed of the facts. The pieces are coming together and I do not exclude (the possibility of) news soon, but for the moment, silence is necessary," Di Lecce added. Entrepreneur Andrea Calevo was seized from his home in the northwestern coastal town of Lerici seven days ago.