The Hong Kong company’s incorporation is among a set of the first publicly available documents revealing her business dealings after avoiding the limelight since fleeing Thailand.

It is not clear what business the company is in. But just four months after she set up the company, Yingluck was appointed chairwoman of Shantou International Container Terminals, a Guangdong-based port operator, other documents show.

“If it is an official [Cambodian] passport, the question would be, how does someone like Yingluck get the passport?” said Chong Ja Ian, a professor of foreign policy at the National University of Singapore.

But Chong said it made sense for her to have acquired it because Cambodia was an “easy option … just across the border”.

“If you want to travel relatively inconspicuously, having a passport such as a Cambodian one would be easy in that sense,” Chong said. “Clearly as neighbours, this could become an issue of contention.”

Around the time Yingluck fled, the Phnom Penh Post quoted an official from the country’s Passport Department as saying: “Ms Yingluck [is] Thai, she is not Cambodian, so I don’t issue a passport to foreigners.”

The Ministry of Interior’s Immigration Department also said then it had no reports that Yingluck, Thailand’s prime minister from 2011 to 2014, had departed for Singapore through Cambodia.

The foreign ministries of Thailand and Cambodia did not respond to requests for comment on Wednesday.

Cambodia is a close ally of China, with deep economic and military links. Yingluck and her brother Thaksin Shinawatra – also a former Thai prime minister – were in China over the weekend to visit their ancestral home in Fengshun township in Guangdong.

Yingluck’s registration of the Hong Kong company also revealed the extent of the family network. While she is the sole director, another company with the exact same name, though with a Bangkok address, was listed as the Hong Kong firm’s founding member.

Pintongta Shinawatra Kunakornwong, and Paetongtarn Shinawatra, daughters of Thaksin, are the major shareholders of a Thailand company called P.T. Corporation Company, according to disclosures from a separate, Bangkok-listed company.

When the Post visited the company’s registered address at the K11 Atelier in Tsim Sha Tsui, an upscale 66-storey office building, the office was occupied by a company called Pacific International Capital. One of its directors is Chen Huaidan, formerly known as Celine Tang.

Staff at the company said they did not know anything about P.T. Corporation, or its connection with Yingluck. “I don’t know why you are coming to us about this company,” a member of staff said. Another company employee later declined over the phone to comment on the relationship.

Former Thai PM Yingluck Shinawatra breaks silence after fleeing country last year

Chen is also managing director of a Singapore-listed property company, SingHaiyi Group, which did not respond to inquiries on Wednesday.

According to SingHaiyi Group’s website, Chen worked as a judicial officer in a district court in Shantou before 1995. She has a bachelor’s degree from People’s Public Security University of China.

She and her husband, Gordon Tang Yigang, were believed to be close to Yingluck, so much so that Yingluck registered her residential address as a luxurious house on The Peak that was bought by the couple for HK$250 million in 2012, according to corporate filings and records from the Land Registry.

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The couple have been previously reported to have close ties with American politicians, and donated US$1.3 million via a US-registered company to support Jeb Bush, son of former president George HW Bush, for his presidential campaign in 2016, according to election financial data provided by a US government agency.

P.T. Corporation Company’s secretary is HYL Secretarial Services, incorporated in the same month as the former.

HYL’s director, Alexander Leung Ho-yin, a lawyer, declined in a Wednesday phone interview to talk about P.T. Corporation Company’s business dealings. He said he had been informed that P.T. Corporation Company would be switching to yet another secretarial company. It would be the second time it had done so, according to records.

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Yingluck, who used to be managing director of a telecoms company owned by her brother and ran a property arm of their family business, took over the Shantou company after Hutchison Port Holdings divested its 70 per cent stake, held via a Hong Kong company called Hutchison Ports Shantou, last December.

On Wednesday, Hutchison Port said it had sold all its shares at an undisclosed price to a Singaporean investor whom it did not name. A spokesman did not say when the deal was made, beyond commenting that it was beyond the company’s control who the investor brought in after the shares were sold.

The other 30 per cent of shares are held by the Shantou arm of China Merchants Port Group. Corporate filings showed Chen was appointed director of Hutchison Ports Shantou on November 11, 2018, with staff from Singapore, mainland China, and three Hong Kong ID card holders.

The filings also showed Thaksin was appointed director of a Hong Kong company called Planet Telecom (HK) Company Limited in 2016.

Thaksin, 69, who is also in self-imposed exile after being overthrown in a military coup in 2006, registered with a Montenegro passport. His residential address is listed as being in Emirates Hill, an upscale district of Dubai, where he has been living for the past decade.

Attempts to reach Yingluck were unsuccessful.