The Port Authority’s longtime practice of underbilling tenants for electricity should be investigated for criminality, a state senator said yesterday.

“This is just another example of a total lack of accountability and oversight,” said Sen. Greg Ball, a Republican on Gov. Cuomo’s Spending and Government Efficiency Commission.

A forensic audit is necessary to see if any laws were broken, he said.

“Executive Director Pat Foye has already stated the agency’s intent to get to the bottom of this issue,” the PA said in a statement.