As many as 10 passengers, who had boarded the ill-fated Air India Express flight in Dubai that crashed in Mangalore, were using fraudulent passports, an Indian Embassy official said.
"We have information that 10 passports were tampered with," Indian Ambassador to the UAE M K Lokesh has been quoted as saying.
He did not go into details, but said the matter was being investigated by passport officials in India.
According to senior Embassy officials, the passports were tampered with and irregularities included false addresses and photos that did not match the user.
However, India's Consul-General in Dubai, Sanjay Verma, said they have not received any official complaint.
"We have come to know through media reports as the passports in question were issued in Kozhikode. Our role is verifying passports issued in Dubai. Whenever such a complaint is made, we will alert the authorities," he said adding that the mission would also help in the probe and offer help to those whose identities had been stolen.
According to local reports, probe has been launched into the travel documents used by the passengers.
The investigation was initiated when a Dubai resident had earlier said that his passport number and other personal details, including his address, were listed as belonging to one of the crash victims.
He came to know about it after his relatives began calling him following the crash.
Valayar Ravi, the Minister of Overseas Indian Affairs, who is visiting the UAE, told reporters that the passport fraud was a serious issue.
"We have seen cases of people pasting their pictures in other's passports. This is something that the Kerala government must to look into in detail," he said.
However, the UAE authorities have expressed doubt that forged documents had been used to board the aircraft.
An Air India Express flight from overshot the runway in Mangalore and burst into flames last Saturday, killing 158 persons while eight others survived.