WASHINGTON—The Senate Intelligence Committee has asked WikiLeaks founder Julian Assange to testify behind closed doors as part of the panel’s investigation into Russian activity during the 2016 election, the organization said Wednesday.

WikiLeaks, a nonprofit antisecrecy organization that publishes government secrets and other nonpublic material, said in a statement posted on Twitter that the group’s legal team is “considering the offer but testimony must conform to a high ethical standard.”

It is unclear how or where such testimony would take place. Ecuador granted political asylum to Mr. Assange in 2012, allowing him to avoid extradition to Sweden over sexual-assault allegations that he denies. The Australian national has been living in Ecuador’s embassy in London since then and still faces arrest in the U.K. if he leaves.

Spokespersons for Democratic and Republican leaders on the Senate Intelligence Committee declined to comment on the invitation, citing a policy against discussing witnesses in the investigation.

At the height of the 2016 U.S. presidential campaign, WikiLeaks published tens of thousands of stolen emails from Democratic Party officials at key moments during the election. U.S. intelligence agencies have said that the Russian government stole and disseminated those emails in part through the organization.