Hamas deliberately delayed the submission of the list of hostages to be released on Saturday, sources told the Saudi state-owned news outlet Al Arabiya on Friday.
The list of names was due to be transferred to Israel at around 4:30 p.m.
The delay was allegedly in retaliation for what Hamas claims is Israel not adhering to agreed-upon humanitarian protocol.
"This would be a violation by Hamas that has no justification, an Israel official told Walla.
The Prime Minister's Office issued a statement saying, "Following the delay in submitting the list of names of the hostages by the Hamas terrorist organization, Prime Minister Netanyahu takes any violation of the agreement very seriously."
Sources told Al Arabiya that Hamas informed the mediators that Israel had failed to enable the entry of mobile homes and tents into Gaza, had not provided the equipment needed to remove rubble, and had not provided enough fuel.
Hamas called on mediators, especially Egypt and Qatar, to put pressure on Israel to ensure the implementation of the agreement, the report added.
Earlier in the morning, Hamas claimed on Telegram that not enough patients had been able to leave the Gaza Strip for medical treatment and that Israel was preventing field hospitals from treating the wounded.
The number of patients who left was, according to the terror group, only 120. Hamas said it has a list of 35,000 patients in "dire need of treatment outside the Strip."
Aid trucks
Hamas also alleged that only 76 aid trucks entered the Strip and that there were no blankets or winter clothes.
The Rafah municipality said it was lacking 40,000 tents and shelter units. It also revealed that 40% of patients with kidney problems died due to lack of necessary treatment.
"Only about 10% of the humanitarian aid stipulated in the agreement has entered the Strip," Hamas added.
The Hamas claims contradict reports from COGAT, which said that since the start of the hostage deal, over 12,000 trucks carrying humanitarian aid have entered Gaza.
The terror group also claimed that a refusal to allow heavy machinery in Gaza would prevent them from accessing the hostages's bodies for release.
"Preventing the entry of heavy equipment and machinery needed to remove 55 million tons of debris results in the inability to remove the bodies of martyrs and open the streets," said Salama Marouf, a spokesman for Hamas' media office in Gaza, according to Les Parisien. "This will undoubtedly affect the resistance's ability to extract the (hostages) who died under the occupation's bombardments."
Tal Shalev and Walla Staff contributed to this report.