Nepal's government is investigating two climbers who claim to be the first Indian couple to conquer Everest.
Dinesh and Tarakeshwari Rathod told reporters last month that they reached the 8,850m (29,035ft) summit on 23 May.
But some mountaineers alleged the couple, who are both police officers, faked their achievement by circulating digitally altered photos of the climb.
If proven to have faked it, they will have their summit certificates invalidated and face fraud charges.
Mr and Mrs Rathod deny the claims, as do the guides who climbed with them.
Nepal tourism chief Sudarshan Prasad Dhakal told reporters that the tourism department had originally certified the couple's summit claims after speaking to expedition organisers and government officials at the Everest base camp.
He told the AFP news agency that the certification procedure relied on photographs taken at the summit by mountaineers themselves, adding that it would be "hard to determine" a fake.
A climber based in the southern Indian city of Bangalore, Satyarup Sidhantha, later told reporters that the photographs presented by the Rathods as "proof" of their climb actually belonged to him.
Contacted by the BBC, Tarakeshwari Rathod insisted that she and her husband had "climbed Everest".
The pair work as constables in the western city of Pune, where police are also carrying out an inquiry.
The Rathods held a press conference on 5 June to announce that their "dreams have been realised" and they had scaled the summit.
But Pune-based climber Surendra Shelke, who is one of a number of Indian mountaineers to have raised doubts over the couple's claim, said his suspicions "were first aroused owing to the time lag between the day the Rathods claimed to have reached the summit and their press conference announcing their achievement".
Others have alleged that the couple could not have reached the summit so soon after they were seen to have arrived at the base camp, and that the photos appeared to show them in two different sets of clothes and boots while on the climb.
However, the chief of Kathmandu-based Makalu Adventure, which organised the ascent, told the BBC he had "no doubt" the couple had scaled the world's highest peak.
"They were taken to the summit by sherpas who worked for my company for several years and they reached the summit on 23 May," Mohan Lamsal told the BBC.
Mr Lamsal said Mrs Rathod had contracted pneumonia on the way down, and his company had sent a helicopter to fly her out from the base camp to Kathmandu for treatment.
"She was in hospital for a week. Only after she recovered, could the couple hold a press meet in India to announce the summit."
Mr Lamsal said Nepalese authorities had issued climbing certificates to the couple after "investigating the matter and interviewing the couple" following complaints by some climbers in India.
"There is some politics going on [in this case]," he added.