The British Army Aid Group's digest of information, Waichow Intelligence Summary No. 16, bearing today's date carries this passage on page 3:
J. D. S. ((almost certainly the HKU Vice-Chancellor, more usually D. J. Sloss)) is returning to Stanley this afternoon after staying out in the F. ((=French= St. Paul's, Causeway Bay)) Hospital, for over four months.
Sloss has revealed medicines urgently needed in Shamshuipo, especially diphtheria anti-toxin.
The information about Sloss has come to the BAAG in a letter signed PREST. They don't know who this is at this stage, but it's Preston Wong, formerly a teacher at St. Paul's College, who will continue to send information until he's caught and executed with 32 others on Stanley Beach on October 29, 1943.
Source:
The Ride Papers, held at the Hong Kong Heritage Project