An aide to Israeli President Simon Peres said on Wednesday a disputed letter from Egypt's President Mohamed Morsy was sent by the Egyptian embassy in Tel Aviv and cleared for publication by officials there.
Egyptian state media on Wednesday quoted Morsy's spokesman as denying any such letter had been sent to the Israeli president.
"We received it from the embassy in Tel Aviv," an official at Peres's office told AFP.
"We checked it with them and we asked them to check whether it was okay to publish it and they got back to us and confirmed it was okay to publish it," he said.
Contacted by AFP, an official at the Egyptian embassy, who did not give his name, said the press attache was "on holiday" and could not be reached for comment.
Peres's office on Tuesday released a copy of a brief note written in Morsy's name in which the new Egyptian president pledged to help revive Israeli-Palestinian peace talks.
"I am looking forward to exerting our best efforts to get the Middle East peace process back to its right track in order to achieve security and stability for all peoples of the region, including the Israeli people," it quoted Morsy as writing.
Last month, Peres sent Morsy a letter of congratulation following his election, and he also sent a second letter of greeting at the start of the Muslim holy month of Ramadan last weekend, his office said.
Peres's office provided a scanned copy of what it said was Morsy's note, with a covering letter with what appeared to be the letterhead of Egypt's Tel Aviv mission, bearing the correct telephone and fax numbers.
Morsy, the country's first Islamist president, has kept Israel at arm's length since he took office on 30 June. Egypt was the first Arab country to sign a peace treaty with Israel, in 1979.
"President Morsy did not send any letters to the Israeli president," his spokesperson Yasser Ali told Egypt's state-owned Al-Ahram newspaper.
An Israeli official, speaking to AFP on condition of anonymity, said adverse reaction in the Arab world may have brought about a retraction.
"It's not surprising bearing in mind the amount of media reaction," he said.