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Mark Heywood KC

"Mark is totally outstanding and in a league of his own."Chambers UK 2023

Call 1985    Silk 2010

Practice Profile

Mark Heywood KC has been ranked as a 'Star Individual' in the Chambers UK Guide to the Bar since 2013 and is a recognised leader at the Bar. He was awarded the Chambers UK Bar Crime Silk of the Year award 2018.

Mark Heywood KC is a former First Senior Treasury Counsel at the Central Criminal Court having held that post between 2015 & 2018. His practice is concentrated on the most serious of criminal work that comes before our Courts, at the Central Criminal Court, Administrative Court, Court of Appeal and Supreme Court. He has appeared in the High Court in civil contempt proceedings, most recently for a claimant Hong Kong Bank where the defendant was sentenced to 18 months and ordered to pay indemnity costs.

Since his role of Senior Treasury Counsel, Mark Heywood KC has primarily been involved in cases of alleged financial misconduct. He leads the prosecution team for the SFO in Op Glacier, the prosecution of a former Airbus subsidiary that was ordered to pay more than 30 million pounds ($42 million) after pleading guilty to corruption over contracts to provide military communications services for the Saudi Arabian National Guard, the trial against the directors is due in January 2023. He has provided pre-charge representations to a client that the SFO suspected had conspired to make corrupt payments contrary to s.1 of the Prevention of Corruption Act 1906 and s.1 of the Criminal Law Act 1977, and was interviewed about his actions in particular, the SFO suspects was involved in actions leading to agreements to make corrupt payments to Nigerian and Malaysian Government Officials, which was discontinued. Further successful pre-charge work includes advice given to an SFO suspect in relation to bribery and corruption involving Petrobas, the value of the contract was said could easily be up to $2 billion. Trial work has including Op Cullinan, a multi-company boiler room fraud involving the sale of diamonds that was dismissed at half time and Op Balaban, a £7m carbon credit fraud that was again dismissed at the close of the crown case.

Mr Heywood has considerable experience in cases of terrorism, large scale corruption, serious & organised crime and offences of homicide. He regularly provides advice to the Attorney General and Director of Public Prosecutions on a range of matters, particularly those being considered by the appellate courts as well as other governmental departments. Other work includes advising upon matters concerning gross negligence manslaughter involving the medical profession and litigation involving the SFO and FSA. He also advises in matters where a private prosecution is sought. 

Cases have included the serial killer Levi Bellfield, Operation Crevice the longest running Old Bailey trial better known as the Fertiliser Bomb plot, Nicola Edginton the mental health patient convicted for the killing of an innocent bystander and the attempted murder of two others in Bexleyheath after a cry for help, the Supreme Court hearing of Gnango [2011 UKSC 59] on transferred malice/joint enterprise, Arthur Simpson-Kent who was sentenced to life for the murder of Eastenders actress Sian Blake and their two children. Recent defence work has included a murder trial in the Cayman Islands (R v.Sanchez).

Mark's Privacy Policy can be downloaded here.


  • 2001 - 2008 - Junior Treasury Counsel
  • 2005 - Recorder
  • 2007 - 2008  First Junior Treasury Counsel
  • 2008 - Senior Treasury Counsel
  • 2010 - Queen's Counsel
  • 2015 - 2018 - First Senior Treasury Counsel


  • South Eastern Circuit
  • Criminal Bar Association


Encrochat case collapses after three years

13 October 2023

Mark Heywood KC, leading Alastair Smith, 2 BR, defended one of those first... Read More

Recent Cases

  • Operation Kandla 2022

    Health & Safety Prosecution under the Medicines Act 1968

    Mark Heywood KC led William Davis in the prosecution of a company that manufactures total parenteral nutrition, which is supplied to vulnerable patients receiving nutrition intravenously. In 2014 a contaminated batch was supplied to hospitals treating severely premature babies. 19 babies developed infections as a result, and one died. After protracted and contentious litigation, the defendant company pleaded guilty to a health and safety offence and to offences under the Medicines Act 1968. The company was sentenced in April 2022.

    BBC News Article.

  • Operation Rayak 2022

    Swedish Gangland Assasination

    Mark Heywood KC led for the Crown in this case involving a Swedish Gangland assassination of a member of a leading figure in Swedish organised crime by a rival group who carried out the shooting by firing 10 shots at point blank range in London in front of the victim’s wife and 2 year old child. This was a carefully planned operation involving protracted surveillance of the victim, disguises, the procurement of semi automatic weapons and ammunition and a clean up operation after the event. 

    News Article.


  • Operation Cullinan 2021

    Multi-Company Boiler Room Fraud

    Mark Heywood KC leading Gregory Fishwick defended in this multi-company boiler room fraud that sold diamonds as investments. The Crown’s case was that a team of brokers including Lewis Bloor from The Only Way is Essex used false identities and pressure sales techniques to con elderly and vulnerable people from hundreds of thousands.The evidence against them included a purported confession that was excluded upon application by the Defence.  The Crown also sought to include companies either side of the Indictment period as evidence of bad character but this again was successfully resisted. The Defence managed to show that the Crown’s disclosure was fundamentally flawed.  Having read the written submissions the Crown initially dispensed with their own expert who had valued the stones and nearly worthless.  Having then considered the supplemental written submissions on disclosure the Crown had to concede that they could not continue to prosecute any and all of the Defendants. Instructed by Bark & Co.

    BBC News Article.

  • R v. Finch - C.C.C. 2021

    Official Secrets Act

    Matk Heywood KC led the Prosecution and subsequent reference of sentence to Court of Appeal of defence contractor employed by BAe Systems who compiled records of highly secret operational information relating to a missile system currently in service with the UK armed forces and abroad and then travelled to Europe to send copies by email to multiple recipients.  Extremely unusual conviction for an offence under section 1 of the Official Secrets Act 1911.

    News Article.

  • Operation Balaban - Southwark 2019

    Multi-Million £ Carbon Credit Fraud

    Mark Heywood KC defended in this £7 million carbon credit fraud listed for three months.  Following extensive legal argument before the close of its case, the Crown, who relied in large part on evidence of the state of the carbon credit market at the relevant time, was forced to acknowledge that its expert fell well short of the standards required in legal proceedings and that there had been disclosure failings such that it was unfair to continue to try the defendants. This case hit the headlines after the alleged expert, Andrew Ager, was discredited leading to many other convictions to be looked into on alleged mis-selling of carbon credits.

    BBC News Article

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Notable Cases