The bodies of all 22 missing from when a tugboat capsized on sea trials on the Yangtze River on Thursday have been recovered.

The Jiangsu Maritime Safety Administration (JMSA) said it recovered the final body tugboat at 2pm on Saturday afternoon, Xinhua reported. Three people out of the 25 onboard were rescued and all 22 others drowned.

On of the three survivors Wang Zhenkai, told Xinhua reporters that he was the interpreter for a 60-year-old Japanese engineer.

"Only the two of us were in the cockpit. We had just finished the load test of the boat's main engine when the vessel suddenly turned on its side. Water immediately flooded in," he said.

The tugboat undergoing sea trials was provisionally registered with the Singapore-flag as the JMS Delta and had been destined a charter with Jurong Marine Services, a subsidiary of Sembcorp Marine.

Three of the 17 Chinese nationals onboard survived, four Singaporeans, an Indonesian, a Malaysian and a Japanese national were among those who died.

JMSA was reported as saying improper operations had caused the casualty.

The vessel was built by Anhui Bengbu Shenzhou Machinery.