The tug boat, built by China’s Bengbu Shenzhou Machinery Co, sank during a sea trial in Jingjiang in Jiangsu province.
Local media reported that the three rescued were Chinese nationals, while the remaining 22 missing included nationals from various Asian countries.
Jurong Marine Services, tug towing subsidiary of Singapore’s Sembcorp Marine (SembMarine), had planned to charter the tug boat.
SembMarine said that three of its employees, two of whom are Singaporeans and one an Indonesian, were among the missing people.
The local Chinese authorities are continuing with search and rescue operations.