The Uttarakhand Forest Department on Friday told the National Green Tribunal (NGT) that it spotted at least seven more Himalayan blue sheep with infection in eyes due to an "unknown virus" at the Gangotri National Park.
The virus reported from the Park in Uttarkashi district was infecting the sheep due to which their eyes were popping out, officials said.
The case first appeared in September 2017 after a year-old blue sheep was found infected and died.
After a petition was filed by Advocate Gaurav Bansal, the Central and Uttarakhand governments were told to investigate the matter.
On Friday, an affidavit filed by the Chief Wildlife Conservator of Uttarakhand, Digvijay Khati, at the Tribunal stated: "Seven blue sheep having an infection in their eyes were spotted and it was observed that the animals were facing difficulty in moving."
But the infected animals could not be caught due to difficult terrain.
The sample of the dead animal sent to the research centre in Bareilly in Uttar Pradesh did not help reveal the reason for the virus, senior officer Shravan Kumar told IANS.
The Gangotri National Park has spread over 2,390 sq km and ranges at an altitude of 2,800 to 7,100 meters above sea level. The park will reopen for the public in April.
Said Dhananjay Mohan, Assistant Principal Chief Conservator of Forest, Uttarakhand: "This is the first such incident for us... It is unclear what exactly it is. We have contacted experts abroad where such cases were reported."
Advocate Bansal, who filed the petition, fears that there are chances of the elusive snow leopard catching the virus as the mountain blue sheep is its main prey.