The suspected white powder package was released to the judge who was captured by Tommy Robinson.
The package was placed by Judge Geoffrei Marson KC at Leeds Crovn Court.
Here Robinson, the founder of the English Defense (EDL), was sentenced, 13 months in May.
It is understood that it was delivered to a general office in court before it was identified as potentially dangerous.
Emergency services went to court at 11.44 am after reports of "suspect shipments".
Police response units, fire and ambulance units attended buildings at Okford Row in downtown Leeds.
The building was not evacuated, and many courts continued to function as usual.
A police spokesman at West Iorkshire confirmed that this thing is now safe.
The spokesman confirmed that the incident is now being treated as "malicious communication".
Robinson – real name Stephen Iaklei-Lennon, on May 25th, arrested Judge Marson for alleged contempt of court.
He was arrested, charged and convicted of shooting people at the Leeds trial and broadcast live footage on social media.
The trial was the subject of a court order prohibiting reporting or broadcasting proceedings in order to prevent predetermination of related trials.
Right-wing demonstrators claimed that failure to report to the trial was part of the institution of concealing the Asian pedophile rings.
Robinson's assassination (35) prompted major protests and threats to the judge on social media.
Robinson was released from jail in August after the Court of Appeal rescinded the court's disregard for a new trial.
Details of the Leeds trial and two other related prosecutions were later published when reporting restrictions were reported.