Oregon attorney general: State investigators used digital surveillance on #BlackLivesMatter
A Black Lives Matter demonstrator (Shuttershock)

Oregon's attorney general is investigating the state's digital surveillance of Twitter users who wrote #BlackLivesMatter and other hashtags and has put one employee on leave, saying she was "appalled" by her department's profiling.

Attorney General Ellen Rosenblum wrote to local civil rights leaders including the president of the Urban League of Portland on Tuesday saying Oregon's Criminal Justice Division, which she supervises, used an online tool to search the Twitter feeds of a number of residents.

The Black Lives Matter movement grew out of the large demonstrations in cities including Ferguson, Missouri; New York; and Baltimore over police killings of unarmed black men.

"When I initially heard about this incident I was appalled," Rosenblum wrote in her letter on Tuesday. She gave no details on the scope of the digital surveillance.

The incident comes as the attorney general is due to report the findings of a statewide task force she is leading on police profiling in Oregon to the legislature on Dec. 1.

It also comes amid a wave of demonstrations at U.S. colleges including Yale and the University of Missouri over the treatment of minority students.

The Urban League of Portland said among those targeted in the surveillance was the Justice Department's own Director of Civil Rights, Erious Johnson, who works in Rosenblum's office and is married to Nkenge Harmon Johnson, the league's president.

In a letter to the attorney general on Tuesday, the league's president said it was "improper, and potentially unlawful" for state investigators to target anyone "merely for expressing a viewpoint, or for being a part of a social movement."

"We are concerned that such unwarranted investigations are racially motivated, and create a chilling effect on social justice advocates, political activists and others who wish to engage in discourse about the issues of our time," Johnson wrote in the letter, signed by other civil rights and labor leaders.

Rosenblum said in her letter she shares Johnson's concerns. She has asked a Portland lawyer to conduct an investigation into improper conduct, her office said.

(Reporting by Courtney Sherwood in Portland, Oregon; Writing and additional reporting by Eric M. Johnson in Seattle; Editing by Daniel Wallis and Lisa Shumaker)