Onetime Obama Administration political strategist David Plouffe and ride-sharing giant Uber are in the crosshairs of a Chicago ethics probe stemming from the release of Mayor Rahm Emanuel’s personal emails.

Plouffe has worked for Uber in various capacities in recent years. In a November 2015 email exchange with Emanuel, made public in December as part of a legal settlement between the mayor’s office and the Better Government Association, Plouffe lobbied the mayor to smooth implementation of a deal that expanded Uber’s reach in the city.

At the time, he was not a registered city lobbyist.

Plouffe did not respond to a request for comment, but Uber acknowledged in a statement to the BGA that it has been in contact with the Chicago Board of Ethics, which recently said it had launched a probe of alleged violations of city lobbying rules that could carry up to $92,000 in fines.

Without naming names, the ethics panel in late January released a so-called “probable cause notice” that described a potential lobbying violation that paralleled the 2015 entreaties to Emanuel from Plouffe on behalf of Uber.

In the communications, Plouffe pressed Emanuel to rapidly fix problems Uber said it was experiencing in implementing a new agreement to allow its drivers to take passengers to and from city airports and McCormick Place.

An Uber spokeswoman acknowledged in January that Plouffe appeared to have violated city lobbying rules. “We take compliance seriously,” the spokeswoman, Molly Spaeth, said in a statement to the BGA. “We’re always working to ensure registrations are accurate and kept up-to-date, but in this case there was an oversight.”

In the new statement from Uber, Spaeth said the company was “in contact with the Board of Ethics and will of course comply with their assessment at the conclusion of their process.”

The Plouffe email came to light as part of a trove of more than 3,200 pages of communications released in December 2016 by Emanuel to settle the BGA lawsuit.

The government watchdog group had accused the mayor of circumventing state open records law by using personal email accounts to conduct public business. In the settlement, the mayor did not admit to wrongdoing but did agree to changes that would make all future business related emails subject to open records requests.

The ethics board said in its notice that an unidentified individual engaged in lobbying on Nov. 20, 2015 but failed to register as a lobbyist until April 13, 2016—the very day that records show Plouffe formally registered as a city lobbyist.

The Plouffe plea to Emanuel was part of an email thread that includes communications dated on Nov. 20 and 21st of 2015. At the time, Emanuel was on a trip to China on the other side of the International Dateline, likely accounting for the confusing date stamps on the emails.

The ethics board notice was first reported by the local news website, The Daily Line.

Plouffe and Emanuel crossed paths in the early White House years of former President Barack Obama, with Emanuel serving as chief of staff and Plouffe as a presidential adviser.

Plouffe eventually left the Obama orbit to join Uber. Plouffe recently began working for a non-profit headed up by Facebook founder Mark Zuckerberg, but still sits on Uber’s board of directors.

In the November 2015 email, Plouffe addressed Emanuel as “Mr (sic) Mayor” and made  it clear that he was aware Emanuel was in China on business. Plouffe went on to complain about problems Uber was having with rules about signage and fees and expressed the hope things could be resolved “before the holiday,” a reference to Thanksgiving that  was just days away.

Emanuel responded by directing Plouffe to work out the problems with two of his top aides in City Hall. “Impossible to address from China,” Emanuel added.

In an interview Wednesday, Ethics Board Chairman William Conlon would not confirm Plouffe and Uber were the subjects of the board notice. He said the issue first came up at a January meeting of the board, which then decided to hold a special meeting on the issue before issuing the notice.

“As matters come to our attention we’re going to deal with them,” Conlon said. “We’re aware of what’s going on in the public arena and if there are any actions that appear to be violations, we’re going to act.”

By law, he said, details of the investigation could not be made public until it is settled or concluded. Both the individual and the company will be able to respond to the probable cause notices.

Conlon did say, however, that the maximum fine could be levied against the unnamed company involved in the investigation was $2,000, while fines against the individual under scrutiny could top out at $90,000.