The banker Charles Hyde is arrested for his role in a plot to help Captain Mateen Ansari escape from Ma Tau-chung Camp. The plot has been infiltrated by Japanese intelligence - in fact, it might have been instigated by them - and a letter written by Hyde with regard to the plan falls into the hands of a pro-Japanese Indian.
Hyde's wide-ranging resistance work included raising money to buy supplies for the camps, smuggling medical drugs into Stanley, organising escapes and sending military intelligence to the British Army Aid Group.
Source:
Ride Papers, 10/37/10 (kindly supplied by Elizabeth Ride)
Note:
This is the most plausible of a number of dates given for Hyde's arrest. Others are April 30, May 3, 'some time in April', 'May' and 'early May'. An undated entry in Harry Ching's diary suggests that Hyde's involvement in plots to free Captain Ansari was known at an early stage in the arrest process:
Hyde's detention was reported, along with that of Selwyn-Clarke and Bunje, in a report that reached the British Army Aid Group on May 3.
For more details of Hyde's resistance work, see
http://brianedgar.wordpress.com/2012/04/20/charles-hydes-resistance-work/
The Ride Papers are held at the Hong Kong Heritage Project: