**Palestinian militant group Hamas has accused Egyptian prison authorities of torturing to death one of its members, the brother of one of its spokesmen.**Hamas said Yusef Abu Zuhri, brother of Sami Abu Zuhri, died on Monday six months after being arrested in Sinai.
The accusation comes at a sensitive moment, as Egypt intensifies its efforts to mediate a reconciliation deal between Hamas and rivals Fatah.
Hamas has demanded clarification from the Egyptian authorities.
None has been provided yet.
Sami Abu Zuhri is quoted by AFP news agency saying his brother died after “weeks of brutal torture” leading to severe bleeding.
Yusef Abu Zuhri was reportedly arrested by security forces in the northern Sinai city of al-Arish after entering Egyptian territory through a smuggling tunnel under the Gaza-Sinai border.
Sami Abu Zuhri claimed his brother had been given first aid at hospital in Alexandria, but was taken back to prison before his condition had stabilised.
Egypt has been repeatedly accused of torturing prisoners by human rights monitors and former detainees.
The government has in the past acknowledged isolated cases of abuse by security officers, but said it was not systematic and the authorities were working to improve prison conditions.