BUENOS AIRES, Dec. 3 (Xinhua) -- Argentina's Navy (ARA) on Sunday said a search vessel had potentially made "metallic contact" with a submarine that sank 18 days ago in the south Atlantic with a 44-member crew on board.

"We are investigating a new contact," Navy spokesman Enrique Balbi told reporters, adding a search vessel was moved earlier in the day to a new location 950 meters deep and "its metallic contact was corroborated by two ships with different sensors."

The ARA San Juan submarine lost contact at 7:30 a.m. local time (10:30 GMT) on Nov. 15 as it was navigating in the south Atlantic. Officials believe an explosion detected on the same day may have sunk the vessel.

According to Balbi, a team of specialists who traveled to Germany to obtain potentially useful data on the German-made TR-1700 submarine, which was acquired in 1985, has returned to apply that information.

Also Sunday, a group of about 50 family members of the lost crew marched in Mar de Plata to demand more information and to push for continued rescue efforts.

Marcela Moyano, wife of one of the crew, told local media, "if they took them away, they have to bring them back."

The group was comprised mainly of crewmen's wives and mothers.

Balbi said the Navy was in contact with the relatives, and had ensured they received the crew's wages.