Father Ralph Henry Siebert was a Maryknoll missionary. He was ordained on 22 June 1941 and assigned to Kaying (Meizhou/Meixian), China. He and his group of newly ordained priests had arrived in Hong Kong just before the Japanese invasion and became trapped in the city and not able to proceed to their inland missions.
After the fall of Hong Kong, he was interned at Stanley Camp. In September 1942, he was released from confinement (see here). In a letter to his mother in March 1943, he mentioned that news of the official Japanese permission to leave Hong Kong for China was received on Christmas Eve 1942. Father Siebert left Hong Kong with a group of Maryknoll Fathers on 13 January 1943 and travelled by boat, train and bus to their inland mission. The group safely reached Kweilin (Guilin) on 2 February 1943.
In 1949, Father Siebert was stationed in Kwangtung (Guangdong) Province.
Obituary/Memorial: https://www.findagrave.com/memorial/258428565/ralph_henry_siebert
Source:
1. Catholic News Service - Newsfeeds dated 23 June 1941. See here
2. The Shanghai Evening Post and Mercury dated 5 February 1943. See here
3. Brooklyn Daily Eagle dated 5 February 1943. See here
4. The Akron Beacon Journal dated 6 March 1943. See here
5. The Akron Beacon Journal dated 17 September 1949. See here