Photos from around 1950 show a couple of small buildings in Statue Square, next to the Supreme Court. With accomodation at premium in the post-war years, these were temporary structures housing the Public Relations Office (later Government Information Service, GIS). Here's a description from the Government's history of the GIS:
Retitled the Public Relations Office, the fledgling apparatus was established on a formal footing as a new government department once a civilian administration took over from the military in 1946. Its first home was an arcade located where the Landmark now stands, on a site once occupied by the illustrious Hong Kong Hotel before its destruction by fire on New Year's Day, 1926. From there it moved to 'temporary' offices in Statue Square, alongside what is now the Legislative Council.
This temporary stay lasted three years, during which the staff dealt with an influx of journalists covering the civil war in China, and the consequences for Hong Kong arising from the Korean War. These were the years when Hong Kong became the destination of choice for foreign correspondents, who established here a comfortable base from which they could make their forays into less salubrious neighbouring countries that offered them news - even sensational news - but fewer modern conveniences and a great deal less security.
They were also the years that witnessed the birth of the so-called 'China watcher'; that alleged expert on Chinese affairs who could raise a damp finger in the air and tell which way the political winds were blowing.
Anxious to remain helpful but apolitical, the PRO arranged press briefings confined strictly to pertinent local topics, gingered up by occasional showings of relevant documentary films. These were staged in Statue Square's non air-conditioned, makeshift structures, often in temperatures above 30 degrees Celsius.
I've guessed dates as 1948-1952, based on the description above. More accurate dates welcome!