Mark Lancaster is investigating a steep increase in the number of operations in private hospitals that are funded by the NHS.
In 2008, five Milton Keynes residents had NHS-funded operations in private hospitals, rising sharply to 319 in 2009 and 2,151 in 2010.
The figures came to light following a parliamentary question by Mr Lancaster, who vowed to make health his priority before the General Election.
The MP for Milton Keynes North said: "These figures are certainly very interesting. While I support the concept of choice in healthcare – something the NHS reforms set out to broaden – I want to ensure that this is not being used as a quick fix by Primary Care Trusts, at the expense of our budgets or publicly-owned facilities."
Mr Lancaster has since written to Dr Nick Hicks, chief executive of Milton Keynes PCT, asking the cost of these operations and how many were undertaken through patient choice.
Constituents have reported being sent for private procedures because of a backlog at NHS hospitals.
The Nursing Times has reported that in some cases it is cheaper to send patients to private hospitals for one-off treatments. However, the British Medical Journal said that the NHS has been overcharged for such procedures in the past.
Mr Lancaster added: "Of course, patients aren't complaining when they are 'upgraded'. But clearly we need to find the balance between delivering excellent care for our patients whilst maintaining an investment in local health economy"