Ocean Infinity, based in Texas, claimed it has completed its mission under the contract with Seoul, worth 4.8 billion won ($4.2 million), according to the Ministry of Foreign Affairs.
Last month, its search ship, the Seabed Constructor, retrieved a voyage data recorder of the Stellar Daisy, which sank in the South Atlantic Ocean in 2017. It departed from Brazil, loaded with 260,000 tons of iron ore, for China.
Eight South Korean and 14 Filipino crew members remain missing.
The company later said bones believed to be from at least one of the missing victims had been discovered, along with an orange-colored object that appears to be work clothes.
It said it has done its part under the contract, and it would carry out additional works, which require sophisticated operations and more time, only with the signing of a separate one, the ministry said.
South Korea's relevant authorities, however, pointed out it has yet to accomplish some tasks stipulated in the contract and asked it to continue the search.
"The government plans to decide its position on the basis of a meticulous review (of the firm's position)," the ministry said. (Yonhap)