Campaign donations made to Portland Mayor Ted Wheeler in 2012 and 2016 by Portland businessman and U.S. ambassador to the European Union Gordon Sondland are under new scrutiny following revelations of Sondland's involvement in ongoing controversy with President Donald Trump and Ukraine.

Portland mayoral candidate Sarah Iannarone called on Wheeler Saturday to return previous campaign donations he received from Sondland.

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Wheeler received a combined $15,500 in donations from Sondland and his business entity, Portland-based Provenance Hotels, in 2012 and 2016, according to ORESTAR, the state's campaign finance database.

Ted Wheeler celebrates his victory in the race to become Portland mayor at Blitz Ladd, a sports pub in Southeast Portland, on May 17, 2016. Bradley W. Parks / OPB

Congressional investigators are interested in Sondland because he and another diplomat had talked to Ukranian leaders about how to respond to pressure from Trump to investigate political rival and former Vice President Joe Biden.

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Sondland indicated earlier this week that he will cooperate with the House impeachment inquiry into the president. He is expected to testify before Congress on Oct. 8.

Iannarone’s campaign director, Gregory McKelvey, said in a press release that “The Wheeler-Sondland relationship has proven to be one of the more lucrative couplings in Portland city politics.”

“Portlanders expect and deserve elections to be free from the money and influence of people like Mr. Sondland who have actively worked to subvert democracy,” McKelvey said.

Wheeler's deputy campaign manager, Amy Rathfelder, said Wheeler is looking forward to hearing Sondland's testimony before making any decisions on the past donations.

"I hope and expect he will testify truthfully when he is called to do so," Wheeler said in a statement. "We will be making a decision once we learn more about the nature of his role."

Listen to the latest episode of "OPB Politics Now," which explains Gordon Sondland's connection to the impeachment inquiry, in the audio player below.

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