Kenya launched an independent investigation on Tuesday into the deaths of black rhinos while they were being transported by the state wildlife service from one national park to another.
A total of nine rhinos died, Tourism Minister Najib Balala said, raising the toll from the eight reported on Friday. Two female rhinos from the group are in good health, he told reporters.
The 11 critically endangered rhinos were among a group the Kenya Wildlife Service (KWS) began moving last month to Tsavo East National Park.
The findings of the inquiry, which will be carried out by other agencies from Kenya and elsewhere, will be ready in about a week, the minister said.
The initial investigation by KWS attributed the rhino deaths to salt poisoning after drinking water at their new habitat.
The inquiry will look into what caused the deaths of the animals, with the minister raising the possibility they may have died from heat stroke.
"Then we will investigate if Tsavo East National Park was the appropriate place to do the translocation," Balala said.
KWS will not take part in the new inquiry to ensure its independence, the minister said.
The death of the animals is another blow for Kenya, where wildlife tourism is a major attraction, after the world's last male northern white rhino died in March, leaving only two females of its subspecies alive.
In May, three black rhinos were killed by poachers in Kenya's Meru National Park.