Their father was an Irish World War II prisoner of war who was incarcerated in Changi with Singapore's first elected chief minister David Marshall.
Now, the children are on the hunt for the descendants of two men who were in prison with their father.
Major Francis J. Murray's elder son Paul, 63, and his sister Villana, 69, landed in Singapore last week.
They met members of the Marshall family on Wednesday, and presented them with a photograph taken in September 1945, after the war ended, of the late Mr Marshall with other POWs, including their father.
In the photo, Mr Marshall is unmistakable, with his familiar furrowed, bushy eyebrows and a trademark pipe in his mouth. The photo was taken around the time a scroll was presented to Maj Murray.
Mr Marshall came up with the citation, lauding Maj Murray's "indomitable struggle" for the health and welfare of the POWs "in the face of obstructive and often vicious Japanese inhumanity" and "interfering swashbuckling medical orderlies".
Mr Marshall and Maj Murray were interned in Changi Prison before they were taken on a three-week journey by ship in May 1943 to forced labour camps in Hokkaido, where they met.
Maj Murray, then in his 20s, was a medical doctor in the British Royal Army Medical Corps. He served in India and later, Malaya, and every night wrote love letters on tissue-thin airmail paper to his fiancee Eileen O'Kane. Most of them reached her at the end of the war.
Maj Murray's letters contain details of a close friendship with an Indian man from Malaya called Krish Nair and a Dutchman from Indonesia, George Reuneker. The unpublished letters have been transcribed by one of his sons, Mr Carl Murray, and add up to 226 pages.
Mr Murray, a retired teacher, said the families of his father's two friends may be living in Kuantan, Malaysia and Java, Indonesia. The Murrays visited Kuantan in 1977 to meet Mr Nair. Mr Reuneker's eldest son, Franklin D. Reuneker, visited them the same year.
Mr Murray said: "Dad was fond of them and held them in high regard, and I've had this desire to share this part of their lives, and what he wrote about them, with their children and grandchildren.
"The letters are rare, and the emotions still jump off the pages since they were written during the war itself, although some of the true horrors and the tone were carefully scripted and masked to prevent detection from the Japanese. He didn't want to upset my mum either."
Mr Murray said some families never learnt what the men went through since the POWs were not encouraged to talk about their experiences as part of their recovery process, unlike today.
You were our only Medical Officer at the Prisoner of War Camps... During these two years – the blackest period of our lives – you were at all times and in all places a genuine friend to each and all of us. ...the tonic of your dry humour which exorcised any tendency to self-pity; your extraordinary memory and intimate knowledge of every one of sometimes more than four hundred men; your ability to maintain discipline, without force to back you, in very trying living conditions; the reforms you introduced and vigilantly enforced to ensure honest distribution of the little food and Red Cross supplies available; the utilisation of your private funds for the benefit of the sick; your unwearying patience with each of us according to his needs; all this, and much else, we shall never forget. Many of us would not be alive at this happy moment but for your care; from the point of view of health all of us owe you more than we can express. ’’
EXTRACT FROM THE SCROLL
In one letter, dated Dec 4, 1944, Maj Murray wrote that Mr Nair had "produced a delightful Indian curry, a cold salad, Christmas pudding - milk and sugar, and one apple, and one orange - and a very lovely greeting card".
The next year, on May 29, he wrote that Mr Reuneker had brought him "two beautiful tulips today - yellow and pink" while Mr Nair had made him "a lovely pair of worn trousers" from an old blanket. "So darling, somebody loves me a little. God bless you, Eileen my darling."
Maj Murray reportedly had once saved Mr Reuneker's life, when he found Mr Reuneker, who was thought to have died of dysentery, still breathing in a morgue in Muroran - a city in Hokkaido.
Maj Murray's letters - with details about hundreds of POWs and the guards in the camps - form a rich treasure trove of historical information on the war.
After the war, Maj Murray married Ms O'Kane, and was made a Member of the Order of the British Empire (Military). They had three daughters and two sons. He was later involved in running a medical practice in Belfast, Northern Ireland, and died at age 80 in 1993. His wife died at 96, in 2009.
Mr Murray and Ms Murray, a retired medical laboratory technologist, have met representatives from the National Archives of Singapore during their visit to share their father's historical data and records.
Last Saturday, they retraced their father's footsteps with Mr Marshall's son and leadership psychologist Jonathan, 48, on a 22km route Maj Murray took from St Andrew's Cathedral to Changi Prison.
In Changi, Maj Murray was in charge of sanitation and was part of a team that carried out spraying to kill malaria-carrying mosquitoes.
The Murray children are hoping that the Nairs and Reunekers, or anyone who might know how to get in touch with them, will e-mail them at firstname.lastname@example.org