Though most hotels contacted were unwilling to say if they had such practices, industry insiders said these procedures are common when a death, either natural or unnatural, occurs.
According to Mr Kellvin Ong, general manager of Rendezvous Hotel, the period that the room will be kept unused will depend on how much cleaning is required and also the demand for rooms.
Religious cleansing rites are carried out 'to give our staff peace of mind', he said. The rites, coupled with room cleaning, could last from a few days to a week.
There are currently no sealed rooms in the hotel and there have been no cases of suicide or murder in the hotel's history, he added.
In Geylang's budget Diamond Hotel, where the naked, bloodied body of a murdered Indian woman was found under the queen-size bed of a fourth-floor room last September, it is also business as usual.
'We will try to assign other rooms before that one, unless the hotel is fully booked,' said an employee who declined to give her name. She recalled that a Taoist priest was called in immediately after the murder and all the room's furniture was replaced.
She added: 'Some customers who remember the news specifically ask not to have that room, and we will accommodate such requests. But we've had no complaints from those who have stayed there so far.'
Diamond Hotel is not the only hotel that has a room with a history.
In 1995, Briton John Martin, a former convict trained in butchery, bludgeoned South African tourist Gerard George Lowe to death with a hammer in a River View Hotel room and dissected the body in the bathtub.
Martin then scattered the body parts, sealed in black plastic bags, into the Singapore River. Mr Lowe's head and arms were never found.
In 1994, Japanese tourist Fujii Isae died in her ninth-floor room at the Oriental Hotel, now known as the Mandarin Oriental Hotel, in Marina Bay.
Two Singaporean men had tailed her and her companion to their room with the intention of robbing them, but Madam Isae choked to death during the attack.
Both hotels did not respond to queries from The Sunday Times.
At the Hilton Singapore hotel in 1974, Mrs Linda Culley was famously killed and chopped up into 13 parts by her husband, Michael Charles Culley, who then sealed her severed body up in a trunk and transferred it to a Cairnhill flat.
The hotel's rooms have undergone revamps twice since the incident, said its spokesman.
A staff member in a five-star hotel chain here revealed that most hotels have a Chinese altar in their basement carparks or in a discreet room in the hotel.
During the seventh lunar month every year, when spirits are free to roam the earth according to traditional Chinese belief, it is common practice for hotels to conduct prayers to 'cleanse' their rooms.
Prayers and cleansing rituals are also held in new hotels before their rooms are opened for occupancy.
Mr Robin Goh, assistant vice-president of communications of Resorts World at Sentosa, said: 'All reputable hotel chains should have such plans in place for all sorts of accidents, from drownings to murders, robberies, assaults and fires.'
He declined to comment on what the integrated resort - which will open early next year - plans to do in the case of such events, as plans are still being firmed up.
As most hotels claim to adopt the 'honesty is the best policy' mantra when it comes to hotel rooms with a history, you can ask before checking yourself into any.
'I believe in being upfront with our guests and letting them be the judge. No point in hiding facts from them as that will only fuel unnecessary speculation,' said Rendezvous Hotel's Mr Ong.