An Israeli journalist is to stand trial for possession of secret military documents leaked to him by a former soldier who is now in prison.

Israel's attorney general, Yehuda Weinstein, announced on Wednesday that Uri Blau, an investigative reporter for Haaretz, is to be charged with unauthorised possession of classified information. A statement from the state prosecutor's office said: "The potential for damage in the unprotected possession of the documents was enormous."

Blau is not accused of endangering the state, although the charges he faces are listed under "aggravated espionage" in the Israeli penal code.

Blau was passed thousands of secret documents by a former soldier, Anat Kam, who copied the papers during her compulsory military service. She was convicted in February of collecting and passing on classified information, and jailed for four and a half years.

Kam copied 2,000 documents, including 700 marked top secret, during her national service as a clerk in the office of a top Israeli general. Among them were papers showing that Israeli military and security officials had authorised the killing of Palestinian militants in operations in which they could have been arrested. Blau's story based on some of the documents was published in November 2008.

Kam was arrested more than a year after publication. The Haaretz journalist remained in London, where he was at the time of the arrest, fearing he would face prosecution if he returned to Israel. He flew back in October 2010 after his lawyers struck a deal with the Shin Bet security service to return the documents.

Two months ago, the state withdrew the agreement, saying Blau had failed to hand over all the documents.

Haaretz said the attorney general's decision was "unfortunate and sets a precedent in terms of its ramifications on the freedom of press in Israel, and especially on the ability to cover the security apparatus".

The Association of Israel Journalists said the move "endangers freedom of the press, which is the soul of democracy".