(Reuters) - U.S. presidential hopeful Elizabeth Warren’s campaign has fired a senior staff member following complaints of “inappropriate behavior,” a campaign spokeswoman said on Friday.

Kristen Orthman said the campaign’s leadership had received multiple complaints over the past two weeks about Richard McDaniel, Warren’s national organizing director, and hired outside counsel to investigate.

“The campaign determined that his reported conduct was inconsistent with its values and that he could not be a part of the campaign moving forward,” Orthman said in an emailed statement.

Orthman did not give details about the nature of the complaints against McDaniel. His firing was first reported by Politico.

McDaniel said in a statement that he would never intentionally engage in behavior “inconsistent” with his own values or those of Warren’s campaign.

“If others feel that I have, I understand it is important to listen even when you disagree,” he said, confirming he was no longer on the campaign team.

Warren’s campaign to win the Democratic nomination for the 2020 presidential contest has been gaining ground in recent weeks.

She has been rising in public opinion polls, and earlier on Friday she reported an increase in fundraising between July and September.

Warren, a U.S. senator from Massachusetts, last week edged past former Vice President Joe Biden for the first time in a major national opinion poll.