Lawmakers in Washington have started an investigation into how construction on the new Yankee Stadium got the green light.

Officials say the investigation focuses on just how much the land underneath the new stadium is worth. The Daily News has reported that the House Committee on Oversight and Government Reform is questioning why the city claimed the area was worth $275 per square foot in one estimate ? and only $45 per square foot in another. According to the paper, city assessors who were interviewed said there is no way the land is worth $275 per square foot.

The discrepancy resulted in big money for the city. Allegedly inflating the value of the land resulted in nearly $1 billion for the city in tax-free bonds.

The city?s finance committee fired back, reporting that factoring in the new Metro-North station and other infrastructure improvements means the land is worth more.