Facebook co-founder Eduardo Saverin made his debut on Thursday on Forbes magazine's list of the 40 richest people in Singapore with a fortune estimated at $2.2 billion.
The Brazilian, who moved to the rich city-state in 2009 and is now a permanent resident, was ranked eighth in a list dominated by Singaporeans whose wealth comes from property, finance and other businesses.
Saverin, 30, was criticised for giving up his US citizenship ahead of the social networking site's stock market debut in May, but he has strongly rejected accusations of being a tax dodger.
Singapore is an Asian technology and finance hub where Saverin mingles with fellow Internet entrepreneurs and is regularly seen in exclusive clubs with a young circle of expatriate and Singaporean friends.
In a statement issued in May, Saverin said: "My decision to expatriate was based solely on my interest in working and living in Singapore, where I have been since 2009."
"I am obligated to and will pay hundreds of millions of dollars in taxes to the United States government."
Saverin was an economics major at Harvard University when he co-founded Facebook in 2004 with three fellow students including the current chief executive Mark Zuckerberg.
Saverin's role in Facebook was famously portrayed in the 2010 film "The Social Network", in which he started out as a close friend of Zuckerberg and provided initial funds for the site before they had an acrimonious split.
The website "Who Owns Facebook?" estimates that Saverin continues to hold a four percent stake in the site worth $3.4 billion based on a valuation of $85 billion for the company.
But Facebook's share price has fallen sharply since it was first traded on the NASDAQ exchange on May 18 at $38 a share.
It closed at $29.34 on Wednesday, on the eve of its first earnings report as a publicly listed firm.