(CNN) -- A U.N. official is calling for a probe into the death of a Palestinian prisoner "while undergoing interrogation in an Israeli facility."
"The death of a prisoner during interrogation is always a cause for concern, but in this case, when Israel has shown a pattern and practice of prisoner abuse, the need for outside, credible investigation is more urgent than ever," said Richard Falk, the U.N. special rapporteur for human rights in the occupied Palestinian territories.
Quoted in a U.N. release on Wednesday, Falk said the "best approach might be the creation of an international forensic team under the auspices of the U.N. Human Rights Council."
Falk said the Palestinian Authority's chief pathologist observed the autopsy carried out inside Israel, and found "clear signs of torture" on the body of "previously healthy" Arafat Jaradat, 30, who died Saturday. Israeli officials had initially claimed Jaradat died of a heart attack, but the preliminary autopsy findings did not include a cause of death, the United Nations said.
A rocket fired from Gaza landed in southern Israel on Tuesday, the first such attack since a cease-fire took hold in November between Israel and militants in Gaza. Militants recently warned there would be retaliation if a prisoner died or was harmed while in Israeli custody.
READ: Palestinians protest inmate's death, warn Obama