The Navy denied the report, saying sonar showed up an unidentified object which could not have been a submarine.

On Monday, 168th Fleet Commander Lee Tung-fang said the object did not dive rapidly to escape detection, but continued on its course at a speed of 2 nautical miles an hour. The data told the Navy that there were no submarines, whales or dolphins involved, Lee said.

The 168th fleet had originally been patrolling off Taiwan’s east coast, but was called to the area off Kaohsiung’s Tsoying base to participate in anti-submarine drills, he said.

The area in the Taiwan Straits was difficult terrain for finding submarines, the senior officer told reporters. His unit had previous experience with locating underwater objects inside Taiwanese territorial waters which later turned up not to be submarines, according to Lee.

Over the past few years, Chinese spy ships have often appeared around Taiwanese waters. Taipei has requested to buy diesel-electric submarines from the United States, but they were not included in a US$6.4 billion weapons package for Taiwan announced by the Obama Administration last Friday.”