The Chief Executive, Carrie Lam, told an RTHK phone-in programme that she can't guarantee that other former foreign residents of Hong Kong who are critical of the Central Government or the SAR authorities might not be barred like Benedict Rogers, a member of the British Conservative Party's Human Rights Commission.
Rogers was refused entry to Hong Kong on Wednesday – the day Lam delivered her first Policy Address.
The Foreign Ministry in Beijing has made it clear that it was its decision to keep him out and that it could decide such issues for all parts of China.
Lam insisted during the phone-in that Hong Kong has the right to decide who to admit or not under the high degree of autonomy promised by the Basic Law.
Pressed if people including former Hong Kong Governor Chris Patten could be barred, she conceded that any foreign national could be barred if Beijing considered it a matter of foreign affairs.
But she said this should be understood in context.
"Under the Basic Law, one country, two systems, the Hong Kong Special Administrative Region has a high-degree of autonomy. We have our own immigration policies, customs and so on.
"But when it comes to foreign affairs then it is a matter for the Central People's Government," Lam said.
She said whether any particular person's entry to Hong Kong "will be regarded as a matter of foreign affairs then of course [it is], if it is regarded as a matter of foreign affairs the it comes under the Central People's Government."
Lam said she couldn't disclose more details of how the Hong Kong Government works with Beijing "because we do have a chapter in the Basic Law which talks about the relationship" between the two governments.
But she said she wanted to clarify any misunderstanding that Hong Kong's immigration is now being taken over by the Central People's Government.