Taiwanese President Tsai Ing-wen may order a probe to look for evidence of negligence and misconduct that could have jeopardized the island’s security after the office of her predecessor, Ma Ying-jeou, failed to hand in records and minutes about how he set up an unprecedented meeting with Chinese President Xi Jinping in 2015.

Lawmakers belonging to Tsai’s Democratic Progressive Party (DPP) said on Tuesday that they wanted an inquiry as they believed that, having being asked to turn over documents, Ma had withheld and blacked out some confidential information regarding the conception of the meeting as well as liaisons with the mainland prior to and after the Ma-Xi summit in late 2015.

Ma met his mainland counterpart Xi in the Shangri-La Hotel in Singapore on November 7, 2015, the first ever one-on-one talk between the leaders of both sides of the Taiwan Strait – which technically were still in a state of belligerence.

Though the two men met in their respective capacities as chairman of the Kuomintang party and general secretary of the Communist Party of China in a bid to expel perceptions of a state-to-state meeting, the KMT had signed up to a tacit agreement that both Taiwan and the mainland belonged to “one China,” which Tsai and her DPP have always disavowed.

Ma said afterward that the meeting was one of the highlights of his presidency.

Ma Ying-jeou (third left) speaks at the landmark meeting with his mainland counterpart Xi Jinping (far right). It was the first time that leaders from Taiwan and the mainland had sat at the same table. Photo: Office of the President, Taiwan

Taipei-based Liberty Times reported this week that Ma didn’t hand over documents detailing how the meeting was negotiated after he stepped down in May 2016. The public was kept in the dark that Ma would meet with Xi in person until just days before the meeting took place.

The paper quoted an anonymous official in the Tsai administration as saying that documents about how Taipei and Beijing interacted and how they arranged the summit were still missing.

The source speculated that Ma could have tapped secret non-governmental channels to approach Beijing, likely via a middleman.

It has been standard practice to keep records of cross-strait communications, including pre-meeting contacts, minutes and so forth, which could help future governments strategize plans and goals in dealings with Beijing.

Under Taiwan law, people found to have destroyed or concealed classified information can be jailed for up to five years, or face a maximum seven-and-a-half-year term if the perpetrator is a government official.

Lawmakers also called into question Ma’s reaffirmation of the “one China” principle at the meeting.

A 2016 file photo shows a Taipei resident watching a televised broadcast of a presidential debate prior to an election that saw the independence-leaning Tsai Ing-wen become the new leader of the self-ruling island. Photo: AP Photo/Chiang Ying-ying

Beijing’s hope to prop up interactions with the pro-reunification KMT toward a deal to lay down Taiwan’s constitutional status and its autonomy for future talks was dashed when Ma’s handpicked candidate to succeed him as president was given a crushing defeat in the 2016 election, which saw Tsai garner an overwhelming share of the vote amid an anti-Beijing groundswell.