More than a month has passed since the tragic capsizing of a Chinese mainland fishing vessel near Kinmen Islands, but representatives from the two sides of the Taiwan Strait are yet to reach a consensus on what caused the vessel to capsize. Not only has the investigation into the incident been delayed, but also tensions across the Strait have increased.

The rigid stance of Taiwan is not conducive to resolving the issue, especially because the mainland's intensified countermeasures and declaration of routine enforcement in the Kinmen maritime area have taken the ruling Democratic Progressive Party on the island by surprise.

The unfortunate event has morphed from individual narratives into a political issue between the "blue" and "green "camps in Taiwan. The blue camp, represented by Kuomintang, aims for eventual reunification with the motherland, whereas the green camp, represented by the DPP, propagates "Taiwan independence". The DPP's indifferent and ever-changing stance and treatment of the incident as a political issue suggest it is concealing the truth.

The DPP should stop dragging its feet over the incident. And Taiwan's judicial authorities must swiftly make public the investigation results, and offer apologies for the incident, if needed, and admit to any law enforcement errors or excesses. The failure to do so will further escalate tensions across the Strait and have repercussions far beyond imagination.

The root causes of the incident are the Taiwan authorities' unilateral demarcation of "restricted waters" off islands such as Kinmen and Matsu and conducting "patrols" around the islands. After Tsai Ing-wen's inauguration as the island leader in May 2016, patrolling by the island's maritime vessels increased in "prohibited, restricted waters", and continues even after Lai Ching-te was chosen the new island leader in January. Worse, the island's maritime officials have been using expulsion, detention, fines, confiscation and other means to "deal" with mainland fishermen "trespassing" into the "restricted" waters.

On Feb 14, a Taiwan "coast guard" vessel pursuing a mainland fishing boat in the waters off Kinmen caused four crew members to fall overboard, with two of them drowning. Initially, the island's "coast guard" claimed the fishing vessel capsized accidentally while evading inspection, and thus denied the use of force but failed to provide any video evidence to back its claim.

However, subsequent investigations revealed multiple collisions between the Taiwan "coast guard" vessel and the mainland's fishing boat, with the surviving fishermen testifying that they were repeatedly hit by the Taiwan vessel, strengthening the belief that the DPP was trying to conceal the truth. The Taiwan "coast guard's" initial silence on the collisions only to admit later that there were "multiple contacts" between the vessels, and misreporting the capsizing time as well as saying they didn't have enough equipment to record the incident, have damaged their credibility.

The Taiwan "coast guard's" actions and statements raise serious doubts. Besides, the statements from the ocean affairs council of Taiwan often lack depth and are issued prematurely, raising suspicion and intensifying tensions across the Strait, which could have negative consequences.

The unfortunate capsizing of the mainland fishing vessel has cast doubts on the Taiwan "coast guard's" transparency. Despite multiple affirmations by Kuan Bi-ling, head of Taiwan's ocean affairs, that the truth cannot be hidden, Taiwan's narrative has shifted repeatedly, oscillating between acknowledging and denying the collisions.

Regrettably, communications between Taiwan and mainland representatives have yielded no results. The DPP's inconsistent statements may well be the main cause of communication crisis. If the DPP wishes to resolve the incident swiftly, it should reveal all the facts about the collision of the vessels. But the DPP keeps emphasizing the "illegality "of the mainland vessel's entry into the waters off Kinmen and the need for "law enforcement", without producing any crucial video evidence of the incident. The contradiction in Taiwan's statements and its attempt to create an illusion of "official" and "equivalent negotiations" between the two sides of the Strait shows the DPP's inability to manage cross-Strait relations.

Communication between the two sides has broken down due to the absence of video evidence and mutual trust. Cross-Strait negotiation mechanisms have come to a standstill. In such a case, the two sides should consider allowing judicial personnel from across the Strait or a neutral third party to re-examine the scene and determine the cause of the death of the fishermen. The cross-Strait judicial assistance agreement has room for cooperation on special cases.

If Taiwan "coast guard's" actions led to the collision and casualties without evidential support, involving mainland judicial personnel or experts, or inviting a neutral third party to investigate the issue could help prevent communication on the incident from being stalled over disputed facts.

The capsizing incident has further strained cross-Strait relations due to the mishandling of the situation by the Taiwan authorities. Although the incident remains unresolved, there's a general consensus, especially among Kinmen residents, that Kinmen should serve as a peace zone rather than a frontline of confrontation. Hopefully, Xiamen and Kinmen will become exemplars of cross-Strait exchanges and integration, contributing to the peaceful and integrated development of cross-Strait relations.

The author is a professor of cross-Strait relations and international relations at Fu Jen Catholic University in Taiwan.

The views don't necessarily represent those of China Daily.