Massport is questioning the $8.75 surcharge Uber charges to take passengers to Logan International Airport, saying in a letter to the ride-hailing giant that any implication the charge comes from the state agency is “patently false.”

“Massport requests an immediate explanation from Uber of the charges on its customers’ receipts,” reads a letter sent Sept. 2 from Massport Acting Chief Legal Counsel Catherine McDonald to Uber CEO Travis Kalanick. “Any representation to the traveling public that there is a ‘Logan Massport Surcharge & Toll’ of $8.75 is patently false.”

Uber riders are routinely issued the charge for trips to Logan. But, according to the letter obtained by the Herald, Massport does not charge Uber such a fee.

The same surcharge is at the center of a lawsuit filed last year seeking class action status in U.S. District Court in Boston.

“The fee is completely bogus,” said John Roddy, a lawyer who filed the suit.

Uber said the fee is meant to offset the time and cost of driving to Logan, where many UberX drivers are not allowed to pick up passengers. In its response to Massport, the company said the name of the fee has been changed to “Airport Surcharge.” An Uber spokeswoman said the company worked with Massport to change the name nearly a year ago.

That change, however, didn’t satisfy Massport, which wants Uber to make clear the agency has nothing to do with the fee.

“Massport has continued to receive complaints even with respect to receipts showing the new wording, as the charge appears to passengers to be assessed by and paid to Massport or the Airport,” agency spokesman Matthew Brelis said in a statement.

Massport is the second state agency to question Uber. In July, the attorney general’s office said it wanted to meet with the ride-hailing company and its competitor Lyft to improve access for people with disabilities.