There's confusion in Israel and Egypt over an apparent exchange of letters between their respective presidents.
On Tuesday Israeli head of state Shimon Peres published a letter apparently sent by Egypt's new President Mohamed Mursi, which was notable for its cordial tone.
It thanked Mr Peres for an earlier letter conveying Israel's best wishes for the Muslim holy month of Ramadan.
The letter said Mr Mursi was "looking forward to exerting our best efforts" to help put the Middle East peace process back on the right track.
But Egyptian officials denied it had been sent, insisting it was a "fake".
Shortly after he took office at the end of June, Mr Mursi denied that he had told the Fars news agency that Iran and Egypt should improve their ties. His office said that interview was a complete fabrication.
A BBC correspondent says the question is whether President Mursi wrote to Shimon Peres or not.
Mr Peres's office says he did, releasing a letter sent by fax by the Egyptian embassy in Tel Aviv, whose official stamp was on the cover letter, apparently from Mr Mursi which was brief but friendly in tone.
The unsigned letter read: "It was with deep thanks that I received your congratulations on the advent of the holy month of Ramadan."
However, within hours Mr Mursi's spokesman declared the letter was a fake.
The BBC correspondent says the debate reflects Mr Mursi's delicate relationship with Israel. Being too cosy will not be popular with the Egyptian public,