An Israeli Bedouin who has been imprisoned in Egypt for more than 12 years on charges of spying has begun an open-ended hunger strike, he said in a handwritten letter in Arabic obtained by the AFP news agency.
"I ask that his excellency, as an ambassador of the State of Israel ... inform Israeli Prime Minister Benjamin Netanyahu and Egyptian President Mohamed Morsi about my hunger strike, which I began on April 23, 2013," wrote Ouda Tarabin in his letter addressed to Ambassador Yaakov Amitai and passed on to the Israeli embassy in Cairo.
He slammed the Israeli and Egyptian governments for what he said was their inaction on his case.
"Both Israel and Egypt have abandoned and violated their pledges and commitments" to upholding human rights, Tarabin wrote, according to AFP.
In particular, "Israel has abandoned its legal and moral commitment to protecting my rights and freedoms and to working seriously towards my release," he said, adding that the Jewish state had "full knowledge of my innocence."
Tarabin, a resident of the southern Israeli city of Rahat, used to travel regularly to Egypt to visit his two sisters in the port city of El-Arish.
However during a trip in 2000 he was arrested and informed that he had been tried in absentia on charges of spying for the Jewish state and was sentenced to 15 years behind bars.
Tarabin, who was 19 when he was arrested, has always insisted he was innocent.
Israel has long called for his release, and on several occasions it has been raised in the context of a possible prisoner swap.
In his letter, Tarabin added that the fact that he was tried in absentia denied him "the legal opportunity and right I am entitled to, under the UN Human Rights Charter and the International Covenant on Civil and Political Rights, to defend myself in light of the allegations against me, to appeal it and to hold a lawful and just trial."
The Israeli foreign ministry declined to comment on the issue.
In October 2011, Israel freed 25 Egyptians in exchange for the release of a US-Israeli called Ilan Grapel, who had been held in Cairo for four months on spying charges.
At the time, Netanyahu ordered officials "to do their utmost" in order to secure the release of Tarabin.
There are about 260,000 Bedouin living in Israel, some 193,000 in the southern Negev desert, 15,000 in central Israel and another 52,000 in the north.