Nairobi, Kenya (CNN) -- One Singaporean national was detained and another released Saturday in connection with an alleged attempt to smuggle raw elephant ivory out of Kenya, according to the Kenya Wildlife Service.
The suspect in detention is expected to be arraigned Tuesday morning before the Makadara Law Courts in Nairobi, the KWS said.
On Saturday, the second suspect was released after investigations by the KWS determined the person is innocent, officials said.
Both men were arrested late Friday when authorities suspected they were trying to smuggle 92 kilograms of illegal raw ivory at the Jomo Kenyatta International airport while trying to board a midnight flight to Bangkok, Thailand.
The K9 unit of the Kenya Wildlife Service made the bust, according to Paul Udoto, a spokesman for the KWS.
"The criminals are getting more sophisticated and so have our systems," Udoto told CNN. "We have enhanced our security systems and entry checks and our dogs are incorruptible."
The Singaporeans are being held at the airport police station and will be arraigned early next week.
Kenya has seen a spike in poaching and trafficking of rhino horn and elephant ivory in recent months, according to environmental groups and the KWS. The rise in smuggling and the effectiveness of Kenya's K9 unit has led to several high-profile ivory confiscations and arrests.
"Globally there is an increased demand so there is a strong motivation for people to kill elephants and rhino," Udoto said.
Poaching has decimated elephant populations in Africa. The World Wildlife Fund estimates that there were as many as 3 million to 5 million African elephants in the 1930s and 40s, but that number has plummeted. In Kenya, the population dropped by 85% between 1973 and 1989 alone.
Anti-poaching efforts have helped stabilize some elephant populations in Africa, but an increased demand, particularly from Asia, has environmentalists worried.
"We need to be more aggressive with poachers and traffickers to stop this problem," Udoto said.