Changes to student loan schemes are expected in the Budget as new figures show 50 students owe about $11 million.
Latest figures from the Inland Revenue Department show they have debts ranging from $200,000 to $280,000.
Another 627,000 have an average balance of $11,900.
The IRD says the total debt by all students is $10.8 billion.
The Union of Students Associations says it does not know what the 50 top borrowers studied to accumulate such high debts.
Tertiary Education Minister Steven Joyce has indicated the eligibility for interest-free student loans will be tightened in the Budget for students over the age of 55.