The family of a Palestinian man, Zaki Mubarak, who recently died in custody in Turkey has rejected the Turkish government's explanation that he committed suicide in prison, calling for an international probe into the incident.

"We want an international committee to investigate the cause of death, which we think is ambiguous," Mubarak's brother told news outlet Asharq Al-Awsat on Tuesday.

The brother said that Mubarak's family has contacted international organisations over the matter.

According to the pan-Arab newspaper, the Arab Organisation for Human Rights in the UK and Europe alleged that Mubarak was tortured to death by Turkish security forces, and called on the United Nations Special Rapporteur on Torture to send a committee to examine Mubarak's body.

The organisation also demanded that the UN stop Turkish authorities from burying Mubarak without conducting an impartial autopsy.

The Istanbul prosecutor's office announced on Monday that Mubarak was found by the guards hanging from the bathroom door in his cell in Silivri prison, Reuters reported.

In a statement, the prosecutor's office said it started an investigation and an autopsy was carried out by the Istanbul Forensics Institute.

Mubarak was arrested on 19 April by Turkish authorities due to suspicion that he was spying for the United Arab Emirates.

Mubarak—along with another man—faced charges of international, political, and military espionage, Reuters reported.

On Monday, the Palestinian embassy in Ankara announced that it is following the case as well as the arrest of another Palestinian by Turkish police, reported Palestinian news agency WAFA.

The embassy said in a statement that Mubarak and Samer Shaaban went missing in Turkey on 3 April, and were found "in Turkish custody facing charges and were to be put on trial."

The embassy said that it was informed by Turkish officials that Mubarak committed suicide.