Investigations have been launched into reports of deaths of 26 elephants in the Maasai Mara Game Reserve in the last three months.
Although the cause of the deaths remains unknown, a conservation group says 11 of the animals may have been poisoned.
According to a report by the Mara Elephant Project (MEP), the deaths of some of the animals in September and November raised concerns among conservationists.
The report in the MEP website and posted on the agency's Facebook page on December 14, shows that seven deaths categorised as "unknown" were recorded in November alone. Evidence pointed to poisoning.
The poisoning, according to MEP, could be blamed on locals "weighed down by wild animal attacks".
In September, three elephant carcasses were found in protected areas of the Mara in just three days, the report adds. Five of the elephants died of natural causes.
"What is disturbing is the rise in 'unknown' causes of the deaths. Eleven of these cases are in the reporting period. However, not all the 26 cases are mysterious. We will harmonise the monitoring of elephants killed illegally every quarter. The next quarter is planned for January," MEP leader Marc Goss told the Nation in an email when asked for details.
"This means we can share the exact data publicly on how they were killed."
According to the report, MEP rangers and Kenya Wildlife Service (KWS) officials took samples from the carcasses and sent them for analysis.
In postmortems conducted by KWS veterinarian identified in the report as Dr Limo, there is no indication of a disease.
It says it is difficult to point out the causes of the deaths. Results from the KWS labs are yet to be made public.
Contacted, Narok County KWS Senior Warden Dickson Ritan referred us to the organisation's spokesperson in Nairobi.
"We were not part of the report, but you can call KWS spokesperson, who is mandated to speak on such matters," Mr Ritan said by phone.
However, our calls to KWS spokesman Paul Masela went unanswered.
He later sent an SMS that read: "I am in a meeting."
Narok county government officials expressed shock at the report, saying they do not know how MEP arrived at the figures.
Maasai Mara senior game warden Moses Kuyioni dismissed the report and questioned the reason MEP released it.
He said officials were in contact with MEP "to explain the reason the report was released without our input and involvement".
"We called the organisation on Sunday and more communication will be released later," Mr Kuyioni told the Nation.
The reserve does not fall under KWS. It is instead managed by the County Government of Narok.
The Nation established that the report was short of indicating if the dead animals had tusks.
"We are looking for evidence that poison was used to kill the elephants. We want to know if a strong pesticide was found in their system," the report added.
The conservation group raised the alarm even as reports of cases of human-wildlife conflicts are on the rise in Narok and Laikipia counties.