An airline has denied asking passengers to pay £20,000 towards the cost of fuel to complete their journey to the UK.
Passengers said they were asked for the money when a flight with Austrian airline Comtel Air from Amritsar in India stopped in Vienna to refuel.
Other passengers have been stuck in India after flights were cancelled.
The airline, which uses Birmingham Airport, said it hoped to get people back to the UK from India as soon as possible at no extra cost to them.
Bhunpinder Kandra, director of passenger services for Comtel Air, told BBC News that “there may have been some operational problem” in Vienna but denied people were asked to pay towards more fuel.
But the Press Association reported him saying: “I have heard what happened, it shouldn’t have happened, and I will investigate why it happened.
“The people who had to pay the money will receive a refund.”
The airline introduced cheap flights from Birmingham to Amritsar in the Punjab, via Vienna, last month.
Birmingham Airport, which said the airline had been operating successfully to Amritsar, said it was concerned and had started an investigation.
But Mr Kandra said he hoped the situation would be resolved “within the week” and that a flight would be leaving Amritsar for the UK on Friday.
Amarjit Duggal, from Great Barr in Birmingham, flew from Amritsar last week after scattering her mother’s ashes.
She said her father, sister and uncle were still there and did not know when they would be able to return home.
She said it was very distressing as they were still in mourning.
“They were due to leave Amritsar on Sunday at 10:30 in the morning,” she said.
“They did not get the information as to what’s happening with the airline.”
‘Distressed British nationals’
Some airline customers who booked through Takhar Travel, in Smethwick in the West Midlands, told BBC News that they were concerned as they have flights booked.
About 30 of the passengers who experienced problems in Vienna, and relatives of people stranded in India, went to the travel agent on Wednesday but said they were told the manager was not available.
Police were called to attend as the small amount of staff in the office became overwhelmed with concerned customers.
A Foreign Office spokesman said: “We are aware that a number of British nationals have been affected by difficulties with Comtel airlines flights from Amritsar to Birmingham via Vienna.
“We have been, and remain, in touch with the relevant authorities including the airline for clarification on how British nationals due to fly in the coming days will be affected.
“Our current advice to anyone affected is to contact their tour operator, travel agent or the airline for further information and about possible alternative arrangements. We would also advise that they monitor our travel advice for India for any updates.
“We took a number of calls from distressed British nationals in relation to this issue and we have provided consular assistance to those who have sought it.”