A right-wing political group accused former Knesset speaker and Jewish Agency head Avrum Burg of treason Sunday in a letter to law enforcement officials for statements Burg made last week that appeared to confirm that Israel possessed nuclear and chemical weapons.

At a conference advocating a nuclear-free Middle East which took place in Haifa last week, Burg said openly that “Israel has nuclear and chemical weapons” and called for an “open and brave public discussion” on the issue, Maariv reported. Israel’s long-standing policy of nuclear ambiguity was “outdated and childish,” Burg stressed, and said that only “regional dialogue, including with Iran” could create a nuclear-free Middle East.

Burg is a former member of the Knesset Foreign Affairs and Defense Committee, and may be one of the few Israelis who have direct knowledge of Israel’s nuclear program.

The Sunday letter from the group, the Legal Forum for the Land of Israel, which was addressed to Israel Police Commissioner Yohanan Danino and Deputy State Attorney Eli Abarbanel, called on the authorities to open an investigation into Burg’s statements, accusing him of “treason” for possibly revealing one of Israel’s key national security secrets.

Also present at the conference was MK Tamar Zandberg (Meretz), who called for a “regional perspective” on the issue and for an end to Israel’s ambiguity on its capabilities. “Israel must become an integral part of the Middle East,” she said, not just connected to the US and Europe.

For decades Israel has maintained a policy of official nondisclosure regarding its nuclear weapons capabilities. The conference, organized by former Hadash MK Issam Makhoul, also featured the mayor of Hiroshima, who has campaigned for the removal of nuclear weapons worldwide.