KUALA LUMPUR: Authorities have conducted flow simulations in the sewer line between the sinkhole on Jalan Masjid India and the Indah Water Konsortium Pantai Dalam plant.
Inspector-General of Police Tan Sri Razarudin Husain said various efforts were made in a bid to find the victim.
"The Fire and Rescue Department had released a bottle into the sewer at the area of the sinkhole to get an estimate of how long it takes the water to flow to the endpoint.
"It takes about four hours," he told reporters after visiting the scene on Tuesday.
He said most of their efforts were being conducted inside the sewers between 12am and 6am to see if the victim was stuck in any of the chambers.
During this time, cameras were placed underground to find the victim, he said.
"The currents are strong in the water chamber.
"During the day, the chamber is almost full," he said, adding that this was the reason for the efforts focused mainly during the wee hours.
Razarudin said a number of agencies have been roped into the search and rescue efforts.
Personnel from the Malaysia Nuclear Agency and the Mineral and Geoscience Department were also scanning the area, he said.
When asked if Kuala Lumpur was safe, Razarudin responded to the question in the affirmative.
"The search and rescue efforts may seem scary, but it isn't actually that way," he said.
Moments after Razarudin spoke to the media, Fire and Rescue Department's K-9 unit was seen entering the scene.
Dang Wangi police chief Assistant Commissioner Sulizmie Affendy Sulaiman is expected to hold a press conference later today evening.
It was reported that high-pressure jetting works to break up debris lodged in the sewer near the sinkhole which swallowed Indian citizen Vijayaletchumy have been completed.
Kuala Lumpur City Hall's media unit in a statement on Tuesday said the jetting work and inspection of pipelines and manhole was done at 6.30am.
However an inspection using a push rod and camera crawler at the manhole in front of Wisma Yakin did not detect the location of the victim.
Tourist Vijayaletchumy, 48, went missing after being swallowed by a sinkhole along Jalan Masjid India last Friday.