At least 135 mutilated bodies of Palestinians returned by Israel to Gaza had been held in a notorious detention centre already facing allegations of torture and unlawful deaths in custody, officials from Gaza’s health ministry have told the Guardian.

The director general of the health ministry, Dr Munir al-Bursh, and a spokesperson for Nasser hospital in Khan Younis, where the bodies are being examined, said a document found inside each body bag indicated the bodies all came from Sde Teiman, a military base in the Negev desert where, according to photos and testimonies published by the Guardian last year, Palestinian detainees were held in cages, blindfolded and handcuffed, shackled to hospital beds and forced to wear nappies.

“The document tags inside the body bags are written in Hebrew and clearly indicate that the remains were held at Sde Teiman,” Bursh said. “The tags also showed that DNA tests had been carried out on some of them there.”