Milner's firm DST Advisors will open an office on the 67th floor of Hong Kong's International Finance Center 2 in June, in the city's business hub, with 10-12 staff according to the source.
The source declined to be named because he was not authorized to talk to the media. A DST spokesman in London had no immediate comment on the matter.
The move comes as investment in Internet technologies gathers pace in China. This month, Milner's Digital Sky Technologies invested $500 million in 360Buy.com, China's largest business-to-consumer website, which raised $1.5 billion ahead of a planned 2013 initial public offering.
In January, DST and Goldman Sachs jointly invested $500 million in Facebook which then valued the social networking firm at $50 billion, according to a person familiar with the matter.