No one was killed in last week’s coup in Thailand, Prime Minister Thaksin Shinawatra was ousted easily, and although the baht and stock exchange wobbled slightly, the military junta has gone out of its way to assure that its business as usual in Bangkok.

That may be true for the average business person, but there is one major Asian businesswoman who faces challenges galore in post-Thaksin Thailand: Ho Ching, the chief executive of the Singapore government-owned Temasek Holdings, which controls a $100 billion-plus portfolio.

In March,, Temasek led a consortium to buy Thaksin out of his telecoms-to-TV family businesses, Shin Corp., in a highly questionable US$4 billion transaction that outraged Thais and played a major role in Thaksin’s demise. As Thaksin banked Temasek’s tax-free cash, many Thais stopped using the businesses Temasek had bought and burnt effigies of Ho on Bangkok streets. And if the deal proved fatal for the Thai Prime Minister, it’s looking like a very big bust for Ho and Temasek too. After less than six months, Shin Corp.’s market valuation is around $1.5 billion less than the Temasek-led team paid.

Thai regulators are investigating the transaction in search of evidence of corruption on Thanksin’s part. Temasek and partners reportedly also face fines up to $2 billion if it is proved – as many suspect—less than that Thai licensing laws were breached. It’s even possible, if unlikely, that post-coup nationalism could get so shrill that the government could nullify the deal and nationalize the assets.

In these post-Enron days where blameless corporate governance is paramount, chief executives who blow so much in six months don’t last very long. But even if her Thai adventure worsens, that’s not going to happen to the 54-year old Ho because she is the wife of Singapore’s Prime Minister Lee Hsien Loong. Ho has been the Temasek’s CEO since 2001, and few in Singapore have publicly challenged her performance, even though Temasek invests taxpayers’ dollars. A few days before the coup, however, a reader of Singapore’s Today newspaper published a letter that was unusually prescient on the topic of Singapore’s alliance with the struggling Thaksin.

“Hitching our investment bandwagon to the first family is a double-edged sword,” wrote Danny Chua in Today. “We can go higher with their rising star but when they fall, we can fall too. Our investment must stand up to scrutiny in the eyes of the law. There must be compliance with corporate governance and transparency. We must be able to sleep peacefully, knowing that we have done the right thing.”

Serious questions abound for a Singapore that often lectures the world about its “best practises” of corporate governance. Temasek is suspected of funding the Thai partners in the Shin Corp. deal, allegedly to avoid breaching foreign investment laws. It is still not known where Temasek paid Thaksin. Thailand’s central bank limits personal cash transfers to US$1 million a year—thus it would take about 2000 years for Thaksin to transfer his pile. Thailand’s central bank governor Pridiyathorn Devakula is regarded as clean guy and he is a contender to be appointed caretaker prime minister by the generals. It wouldn’t do for him – or the generals – if rules had been bent. Thaksin presumably knew that, so it raises questions whether the Temasek consortium paid some of the funds offshore, in a foreign tax haven perhaps, avoiding Thai rules altogether.

In sum, the coup was anything but “smooth as silk” for Ho and Temasek. They have lost their main political ally in Bangkok and will need to find new ones as the government’s investigation of Thaksin deepens. Thaksin banked his billions months ago and, now in gilded exile in London, is unlikely to offer to return Temasek’s cash. If Temasek and Thaksin fall out, the legal implications are intriguing. For the moment however, the silence from Temasek has been deafening. It simply says it is “monitoring events.” It might have added: "anxiously."