Gaza Strip - The past year has been exhausting for Umm Abdeldaim Abu Lebdah, whose only son went missing in Egypt's Sinai Peninsula in August 2015, along with three other young men.

"I see the world through my son's eyes; his abduction has turned my life into a living hell," the 53-year-old mother told Al Jazeera.

The four men, members of a Hamas naval commando unit, were abducted by masked gunmen just outside of the Rafah crossing terminal in Egypt while en route to the Cairo airport.

Her son, 25-year-old Abdeldaim, had been bound for Turkey to pursue postgraduate studies in engineering. Families of the four missing men say that contact was lost on August 19, 2015, after gunmen stopped the bus they had boarded outside of the Rafah terminal.

Where they were taken from there remains unclear.

"It is really mysterious that the bus was ambushed while it was escorted by Egyptian soldiers, and in an area that fully lies under Egyptian sovereignty," Mohammed Abu Libdah, Abdeldaim's uncle, told Al Jazeera.

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The crisis has fuelled tensions between Hamas, that rules the besieged Gaza Strip, and the Egyptian regime. For months, Egyptian authorities have denied any involvement in the men's disappearance, instead blaming armed groups in the Sinai.

However, a newly leaked photograph purports to show Abdeldaim and one of his friends, Yasser Zanoun, imprisoned at an Egyptian security facility in Cairo.

The apparent confirmation that they are alive has partially comforted the men's families, but their appearance in the photo - tired and half-naked in an overcrowded cell - was distressing, Abdeldaim's mother said. After viewing the photo, she collapsed and was taken to hospital.

Two months earlier, Hamas had sent a delegation to Cairo to inquire about the four missing men. The delegation asked Egyptian intelligence officials to release their location, but the trip was to no avail.

Hamas parliamentarian Yahia Mousa told Al Jazeera that international organisations and foreign ambassadors - the identities of whom he would not specify - have also urged Egypt to resolve the situation, but little progress has been made.

"The Egyptian attitude suggests that Hamas must pay a price in return for any information regarding the men," Mousa said, alleging that Egypt has indirectly acknowledged holding the men as political hostages, placing conditions on their release.

The conditions, Mousa said, are related to Egypt's claims that Hamas has been supporting armed anti-government fighters in the Sinai - allegations that Hamas categorically denies. Egypt is pressing Hamas to join the Egyptian army in battling against the fighters, he said, noting: "We are not willing to fight and clash with these groups on behalf of the Egyptian army."

According to local media outlets, Egyptian officials insisted that they do not know of their whereabouts, nor has any group claimed responsibility for their alleged kidnapping. However, several Arabic-language news outlets have cited an unnamed security official as claiming that the Province of Sinai - a militant group affiliated with the Islamic State - kidnapped the four men as a bargaining chip in negotiations for the release of 50 Egyptian Islamists said to be held in Gaza’s prisons.

Last June, an Egyptian court cancelled a previous ruling labelling Hamas as a terrorist group. This move raised speculation that relations between Egypt and Hamas might improve.

We call on the Egyptians to handle the matter quickly, and if they are sure that they have charges against our relatives, why not put them on trial in front of everyone? Jihad, brother of Yasser Zanoun

The family of Yasser Zanoun expressed hope that the newly released photo could finally put an end to the crisis.

"We call on the Egyptians to handle the matter quickly, and if they are sure that they have charges against our relatives, why not put them on trial in front of everyone?" the young man's brother, Jihad, told Al Jazeera.

Yasser, who had been leaving Gaza for Turkey to obtain treatment for a severe leg injury, had been crossing the border during a rare opening of the Rafah terminal. His abduction has distressed the family, including Yasser's four-year-old son, Mahmoud, who refuses to let his father's photo leave his hand, Jihad said.

The families of the other two men - Husain Abu Zibdah and Abdullah Abu Jabin, who were not pictured in the photo - are uncertain of their fates. Husain's six-year-old son, Islam, who is about to start school, expressed dismay that his father would not be able to accompany him on the first day.

"We anguished over how to explain the situation to his young children," Husain's brother, Anwar, told Al Jazeera.

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Over the past year, the four families have held several protests and mounted a public campaign to raise awareness of their plight, asking the Palestinian Authority (PA) to step in.

But the families were infuriated when PA President Mahmoud Abbas in December ordered former Justice Minister Saleem al-Saqqa to step down after Saqqa asked the Egyptians to investigate the disappearance of the four men.

Contacted by Al Jazeera, a spokesperson for the PA declined to comment on the case.

Families of the four men, meanwhile, fear that poisoned politics could cause the crisis to drag on indefinitely.

"We want our sons back. It is unfair that we go through this adversity while they [Egyptian officials] calculate how they can get the most out of the crisis," Umm Abdeldaim Abu Lebdah said in a broken voice.