A Chinese man who was arrested on Sunday for unlawfully entering Taipei harbour in a speedboat is a former navy commander who may have been on a military probe, Al Jazeera reported.

According to the Taiwan authorities, after travelling in his little boat across the 160 km Taiwan Strait, which divides the island nation from China, the guy was taken into custody by Taiwan’s coast guard.

He told the authorities that he wanted to defect. However, officials said, he might have been gauging Taiwan’s reaction to his strategy.

An investigation and questioning is underway of the 60-year-old, who Taiwan claimed was an officer in China’s People’s Liberation Army Navy with the surname Ruan, reported Al Jazeera on Tuesday.

Kuan Bi-ling, the president of Taiwan’s Ocean Affairs Council (OAC), who is in charge of the coastguard, told the reporters at parliament that he was “quite elegant and well presented.”

Speaking to reporters, Taiwan’s Defence Minister Wellington Koo stated that the boat incident might be another instance of China’s “grey zone” operations against the island.

‘Grey Zone tactics’ are referred to as irregular tactics to evaluate an area without engaging in open combat and have included China sending boats and military aircraft above the self-governed island.

Previously, in March, two Taiwanese fishermen entered Chinese territorial seas when they ventured into the area around the Kinmen Islands, which is adjacent to China’s shore. One of the military officers from Taiwan, is still being held captive in China, while the other was freed shortly after, according to Al Jazeera.

The most recent incident occurred while tensions between China and Taiwan were on the rise and there were worries that China may use force to assert its claim on the island.