Supreme Court's four judges including Cheif Jusitce of Pakistan (CJP) Qazi Faez Isa also recived "threatening" letters containing a suspicious powder on Wednesday.
The development came after the Islamabad High Court and Lahore High Court judges received the same letters yesterday and today..
The advocate general confirmed that the four justices of the supreme court including CJP Justice Qazi Faez Isa, Jusitce Aminuddin, Justice Jamal Mandokhail, and Justice Athar Minallah received the letters today.
The 24NewsHD TV channel reported that all the four letters were sent on April 1 in which suspicious powder was found.
All four suspicious letters were handed over to the CTD for investigation.
Earlier, CTD Investigation Wing started probe into the suspicious letters received by the LHC judges Wednesday.
The CTD personnel arrested an employee of a private courier company who delivered the letters at the LHC and sent the powder extracted from the letters for forensic analysis.
After the Islamabad High Court (IHC), the Lahore High Court (LHC) judges also received the same letters having threatening signs and suspicious powder inside, 24NewsHD TV Channel reported on Wednesday.
According to the report, the LHC administration received the posted suspicious letters in the names of 4 judges who were included in the LHC Administrative Committee.
The sources said when the staff opened these letters, there was powder and a threatening sign inside.
The LHC administration immediately informed the police high-up about the details of the threatening letters to the judges.
After getting information, DIG Operations Ali Nasir Rizvi along with the forensic experts' team reached Lahore High Court. The forensic experts' team has started an investigation to identify the nature of the powdery substance.
Yesterday, at least eight judges of the IHC reportedly received suspicious letters and the staff of two judges discovered a powdery substance upon opening it.
The sources stated that authorities are currently investigating the nature of the powder. Police experts are leading the investigation to determine its composition and potential hazards, the sources added.
In addition to the powdery substance, the letters were found to contain a threatening sign, court sources revealed.
The letters were allegedly signed by a woman named Resham, the wife of Waqar Hussain.
It has also been revealed that the woman who sent the letters to the Islamabad High Court judges did so without including an address.
Reporters Amanat Gishkori, Farzana Siddique and Irfan Malik