A law firm and three solicitors face disciplinary proceedings relating to claims of torture by British troops in Iraq.
Leigh Day and three solicitors, Martyn Day, Sapna Malik and Anna Crowther, will appear before the Solicitors Disciplinary Tribunal (SDT) in London later.
They face 19 misconduct charges over claims of torture and murder by British troops during the Iraq War, along with prohibited payments to a third party, a person known as Z.
Among the charges is an allegation of improper conduct at a 2008 press conference involving disgraced lawyer Phil Shiner, where it was claimed British soldiers had abused Iraqi civilians during a 2004 battle.
Mr Shiner was struck off in February for dishonestly pursuing torture and murder claims against British troops
A total of 22 charges against him, including 12 he had denied or partially admitted and five of dishonesty, were found proved by the SDT last month.
He was found to have paid more than £25,000 in referral fees for cases to an agent, named as Iraqi human rights campaigner Mazin Younis, in the SDT judgment.
Mr Shiner also acted "recklessly" at the press conference in February 2008 by claiming the British Army had unlawfully killed, tortured and mistreated Iraqis during the Battle of Danny Boy.
The 60-year-old, from Birmingham, had said he could not give evidence because he was unwell, but this was dismissed by the tribunal.
Leigh Day argued Mr Shiner's medical details should be disclosed to them by the Solicitors Regulation Authority (SRA) in case they were "relevant to the context that those findings and admissions were made".
But the panel dismissed the application, saying the medical evidence was "not relevant".
The tribunal is expected to last seven weeks.