For the past two years, Manas Sharma's life revolved around one goal - cracking the tough exam that would get him admission to a medical college in India so he could become a doctor.

But the exam - the National Eligibility Entrance Test (Undergraduate), known as NEET-UG - has been at the centre of a controversy this year following allegations that the question paper was leaked.

On Tuesday, the federal government's National Testing Agency (NTA), which conducts the exam, cancelled the test that took place on 3 May because of an investigation into the allegations.

The agency also said that a new date for a retest would be announced next week.

"It just left me shocked," says Sharma, who sat the exam on 3 May.

"Since October, I have been studying 12 hours a day - not watching films or even hanging out with friends. That's what it takes to get into a good medical college," Delhi-based Sharma said.

He was expecting to score 615 marks out of 720 - an assessment that he said was based on unofficial answer keys released by private coaching centres after the exam.

A score like that, he said, could have gotten him admission in one of the top medical colleges in India.