A German tourist found a bag belonging to an Italian who missed the flight that Vittorio Missoni was on when the plane vanished shortly after takeoff on Jan. 4 near Venezuela, said Norman Serphos, a spokesman for Curacao's prosecutor's office.
Curacao lies about 200 miles (320 kilometers) west of the resort islands of Los Roques, where the plane departed for Caracas, the capital of Venezuela.
Serphos said the German tourist had contacted the owner of the bag in Italy, who in turn called police in Curacao.
Local police received the bag on Friday and are working with authorities in Venezuela and Italy, Serphos said.
The bag was found along Curacao's rocky north coast, a place sometimes frequented by tourists, Serphos said.
An official at the Italian Embassy in Caracas confirmed that a bag had been found in Curacao. The official spoke on condition of anonymity because he wasn't authorized to comment publicly on the matter. He said the embassy planned to make a statement later.
The BN-2 Islander plane was carrying Missoni, three other Italian tourists and two crew members when it vanished.
Italy's air safety agency has said the pilot had an expired medical fitness certificate and that the company operating the aircraft wasn't yet authorized to fly. However, the National Flight Safety Agency said that neither factor yet is being blamed for the disappearance.
Seven minutes after takeoff, the pilot reported that he was at 5,000 feet and 10 nautical miles from the Los Roques airport, according to the agency. The last radar readings showed the aircraft accelerating at 5,400 feet before it quickly lost altitude and speed, veering to the right until it disappeared from the radar.
Associated Press writer Ian James in Caracas contributed to this report.