U.K.'s Ministry of Defense on Tuesday refuted claims that a Royal Navy helicopter was chasing an Argentine submarine when it went missing off the southern coast of Argentina Nov. 15. The claim was made by Jesica Medina, the sister of one of the 44 missing sailors on board the vessel.

According to Medina, she had received a "strange" message from her brother, Roberto Daniel Medina, days before the vessel's last known communication, saying that the ARA San Juan submarine traveled close to the Falkland Islands and that a Royal Navy helicopter was trying to track them.

"On Monday an English helicopter was looking for us, and yesterday the Chileans, there has been a lot going on," second sub-officer Roberto Medina told his sister in the message, adding that they were now heading for home.

In an interview with Argentina's La Gaceta newspaper, Jesica Medina said that "many" other families of other missing crew members also received messages that they had been fleeing a British helicopter at the time of their disappearance.

"It was a strange message in which he told us a British helicopter and a Chilean ship had been chasing them," she said. "I don't know how close they got to the Malvinas, and I don't know what the political situation is like. That's what he told us and that is what we were left with."

Jesica Medina said that she initially did not disclose about the message because she didn't feel "capable," but later decided to make it public in the hopes the lead investigator would see the report.

"I think we're not the only family that has something like that, I think there are a lot of them. Judge Yanez will have to investigate," she said, referring to the lead investigator.

A Ministry of Defense spokesman told the Daily Mail: "This story is completely untrue."

The ARA San Juan's last known location was about 300 miles from Argentina's southern coast and was believed to have disappeared following a battery failure. Despite a multinational search to find the submarine and its crew, the vessel is yet to be found and its crew are feared dead. 

Earlier this week, authorities said a “new object” was located during the search for the missing submarine.

“A new object has been found at 1,000 meters (3,280 feet) with sonar search equipment in the South Atlantic,” Argentine navy spokesman Enrique Balbi told reporters Monday, according to Agence-France Presse. “It is being looked at to determine if it could be the Argentine sub.”

Another object was also found at about 700 meters, or 2,296 feet, Balbi said. Underwater sonar previously detected a “metallic” 196-foot object some 1,565 feet below sea level. A Russian submersible sent to investigate further, however, found that the object was a sunken fishing vessel and not the ARA San Juan.

It is believed that the crew on board the vessel were dead as experts say the crew only had up to 10 days of oxygen if the sub remained intact under the sea. An explosion was later detected around the time and place where the submarine last made contact.

“The extreme environment, the time elapsed and the lack of any evidence eliminates a scenario compatible with human life,” Balbi said last month. “These are hours of intense pain and anguish [for relatives] in light of the loss of their loved ones, our 44 comrades.”

In a special report Monday for the Miami Herald, Lance Wills reported from the coastal city of Comodoro Rivadavia in southern Argentina that the country remains distraught about the missing submarine and quoted an Argentine naval officer, Juan Parant.

"We've never lost one before. Our submarines operate in the quiet. Most people don't know they're even out here. But everyone in Argentina is talking about submarines now,” Parant said.