A doctor at Gaza's largest hospital Al-Shifa told AFP that the facility's director and several other medical personnel were arrested by Israeli forces on Thursday.
The director, Mohammad Abu Salmiya, has been frequently quoted by international media about the conditions inside Al-Shifa, a major focus of Israel's ground offensive during its indiscriminate war on the strip.
The Israeli army, which raided the hospital last week, has claimed that Hamas fighters used a tunnel complex beneath the facility in Gaza City to stage attacks. Hamas and hospital officials have repeatedly denied the claims.
"Doctor Mohammad Abu Salmiya was arrested along with several other senior doctors," said Khalid Abu Samra, a chief of department at the hospital.
An official in the Gaza health ministry specified to AFP that one other doctor and two nurses had been detained, as well as the hospital director.
In a statement, Hamas said it "strongly denounces" the arrest of Abu Salmiya and his colleagues, calling on the International Committee of the Red Cross and other international organisations to work towards their "immediate release".
Instructions to evacuate the hospital were issued on Saturday, prompting the exodus of hundreds of patients and displaced towards the supposedly safer south of the Palestinian territory.
Abu Salmiya told AFP last week that he had received the evacuation order from Israeli forces after having refused a previous one.
But the Israeli army claimed the evacuations were carried out at the "request" of Abu Salmiya.
The military released an audio recording presented as a conversation between Abu Salmiya and a senior Israeli officer in which the two men blame each other for the evacuation.
Israeli officials claim Hamas operated a command centre in tunnels under the hospital for years – an accusation the Palestinian movement and medical personnel reject.
On Wednesday, Israeli soldiers escorted journalists to a tunnel shaft they claimed was part of a vast underground network used by Hamas.
Al-Shifa Hospital has been the scene of an extended Israeli special forces operation as part of its war on the Gaza Strip, in which more than 13,000 people have been killed.
Hamas's surprise 7 October attack killed about 1,200 people, with around 240 taken hostage.
Israel has been occupying Palestinian territory, including Gaza, for decades and has carried out several previous assaults on the strip.