Police are investigating allegations of food contamination at a crown court.
Judges' lunches at Snaresbrook Crown Court in east London were allegedly spiked with urine, according to a report.
The Sun newspaper said it was feared someone with a grudge against the justice system had launched a revenge campaign.
Traces of urine were believed to have been found in soups, salads and sandwiches, it added.
A private dining room known as the advocates' lounge has been shut down until further notice, the newspaper said.
Staff working there are believed to have been suspended while the probe goes on, it said, adding that all are thought to have been supplied to the court by Eurest Services, a division of catering giant Compass.
A spokeswoman for Eurest Services said it was "aware of a suspected case of food contamination".
She added: "We are currently investigating the matter and therefore cannot comment further at this stage. Health and safety is our number one operational priority, we have robust policies in place and take such matters extremely seriously."
A spokesman for Scotland Yard said: "Police were called at approximately 4pm on Tuesday January 17, and are jointly investigating an allegation of food contamination, with Redbridge Council. There have been no arrests, and inquiries continue."
A spokesman for HM Courts and Tribunals Service said: "It is a matter for the police."