Contrary to popular belief, tomb hunters Charles and Raymond Goh, who discovered a 150-year-old grave in the heart of Outram last month, rely on cold, hard facts and not the supernatural to lead them to their next find.
Likening themselves to fictional detective Sherlock Holmes, the co-founders of Asia Paranormal Investigators (API) spend their weekends poring over old records and trekking through forgotten forests and graveyards.
The specialised heritage hunters may not have come face to face with a ghost but they have found hundreds of graves, including those of pioneers Seah Eu Chin and Chia Ann Siang.
Said Mr Raymond Goh, 50: "We set out to break taboos and show Singaporeans that cemeteries are wonderful repositories of historical data. The multi-ethnic make-up of some of our old graveyards testifies to how Singapore was at the crossroads of the East and can reshape how we interpret our history."
Singapore Heritage Society president Chua Ai Lin said the Gohs have become authorities on old tombstones.
"They are driven by their passion and have spent years slowly accumulating wide-ranging knowledge, sometimes with no specific goal in mind, resulting in surprising discoveries and finds.
"We need to acknowledge their skills and recognise them as serious researchers," she added.
The brothers said they work well together. The strong suit of younger brother Charles is map work. He digs up land records detailing past and present occupants of an area. By comparing old and new maps, the 46-year-old construction safety manager is able to narrow down search areas.
Older brother Raymond, a pharmacist and Hwa Chong alumnus well-versed in Chinese culture, then writes a report of the tomb inscriptions, lineage and significance of each grave.
They have found the graves of lesser-known Singaporeans, whose stories are no less important, they said. These include rickshaw puller Low Nong Nong, whose 1938 grave was found in Bukit Brown Cemetery last year.
Low had been on strike with other rickshaw pullers seeking better wages and died in a confrontation with police. The tombstone noted that fellow coolies pooled money to bury the penniless Low, who had no kin here.
The brothers credit their late taxi driver father and 73-year-old mother, a former kway chap hawker, for instilling a love for reading, learning and research in them and their three other siblings.
Mr Charles Goh said he spent his younger years reading voraciously, borrowing books from the old National Library in Stamford Road.
"Our noses were always buried in books. At the dinner table, our mother would tell us to put our books away," said the younger Mr Goh, whose wife, 44, works in retail.
After buying his first computer in 2001, he dived into local urban legends online.
"There was so much misinformation... I wanted to be the alternative voice in the midst of all the rumours," he said.
This led him to set up API with his older brother in 2005. Both conducted tours at supposedly haunted houses and graveyards. They would relate findings from their interviews with witnesses and use coroner's reports to debunk myths of hauntings.
These trips, including tours to Bukit Brown, sparked a desire to find out more about Singapore's ancient relics.
The brothers have since helped about a hundred Singaporeans locate their ancestors' graves, at no cost. They said it is meaningful to see families connecting with their relatives despite the decades.
Mr Raymond Goh's wife, Angeline, 40, a housewife, sometimes jokes that he spends more time with the dead than the living. But, like their children aged 14, 19 and 20, she said she is proud of him.
The brothers hope the likes of the National Library Board and National Archives of Singapore will recognise them as serious researchers and open their archives and resources to them for free.
They are also calling for more support from clan associations, educational institutions and the National Heritage Board for their research work at Bukit Brown. The older Mr Goh said: "We are on the threshold of discovering even more heritage gems in our backyard and we need back-up."