Samart embarked on expansion into the neighbouring country through Charoenrath Vilailuck's personal connection to Cambodian politician-cum-businessman Sun Chanthol.
Chanthol, a Harvard University graduate, was known for his business smarts. He was the public-works and transport minister until last year.
Charoenrath is the older brother of Watchai, CEO of Samart.
Through the connection with Charoenrath, Cambodia handed the company a concession for the nascent mobile-phone market, and Cambodia Samart Communications was born in 1992.
The following year, Cambodia Shinawatra was set up as a subsidiary of Shin Satellite to penetrate the mobile-phone market in the neighbouring country.
Telecom insiders recall Chanthol was a close aide to Prince Norodom Ranariddh, who was prime minister before Hun Sen took power.
"The connection led to the air-traffic-control concession going to Samart in 2001," a source said. "Samart indeed entered the country before Thaksin."
In that year, Cambodia Air Traffic Services (CATS) was formed to run the 22-year concession. Thaksin was present at the ceremony when Cambodia extended the concession from 15 years to 22.
Back then, Shin Corp, Thaksin's family business, faced troubles in expanding there when the mobile-phone concession was shortened.
From CATS, Samart moved to building a power plant to support the Siam Cement Group's new plant there.
The Vilailuck family also won a 99-year concession to open a museum in Siem Reap, but it has performed badly financially, because visitors tend to flock to a South Korean museum nearby.
This explains why Watchai was in the hot seat and cried for help when his business was tampered with by the Cambodian government. Without any political involvement now, he is seeking to further distance Samart from politics.