The security officers presented a letter that they said allowed them to take the office’s computer and documents.
According to a press release from the One Million Signatures Campaign, which seeks to change discriminatory laws aimed at women, Ebadi refused to surrender her computer and case files, citing the confidential nature of the work of lawyers.
She said the act of surrendering client files to government officials would breach that confidentiality.
The One Million Signatures Campaign said, "This latest assault seems to be part of an ongoing campaign of harassment of Shirin Ebadi, human rights defenders as a whole, and reflects the worsening situation of human rights in Iran."
The latest raid follows the closure of the Defenders of Human Rights Center on December 21, of which Ebadi is a founding member.
The center brings together a number of prominent human rights lawyers and offers free legal advice.
Ebadi told RFE/RL that she believes the December 21 raid was in retaliation for her center's influence with the United Nations.
"For the past two years, the Iranian government has not been allowing UN human rights observers to enter the country," Ebadi said. "And, therefore, all the reports we have been submitting about violations of human rights in Iran have been attracting significant attention from the international community.”
Ebadi said the activities of her and her colleagues "have never depended on one office or a building" and that they would continue to defend human rights in Iran despite pressures by the authorities.