Strategic Advisory and Dispute Support for General Counsel and In‑House Legal Teams

Olesya Prantyuk is a Chartered Certified Accountant with over 15 years of experience in finance and accounting, including more than a decade in disputes. She has been appointed as a named and shadow expert, and has assisted named experts on more than 50 occasions in forensic accounting and commercial damages matters.

Olesya has worked across litigation and arbitration forums, including LCIA, ICSID, ICC and SIAC, on high‑value matters with disputed sums exceeding $5 billion. Her experience spans sectors including energy, aerospace, TMT and financial services, and includes complex valuation, fraud and corruption‑related cases. She is fluent in Ukrainian and Russian and advises on matters across Central and Eastern Europe and the Middle East.

Matt Ösund‑Ireland is a Chartered Environmentalist with over 30 years’ experience advising commercial organisations, governments and financial institutions on environmental strategy, compliance, impact assessment and due diligence. His expertise spans air quality, climate change, carbon footprinting and climate‑related risk.

Matt has provided expert evidence at planning appeals and to the House of Commons Select Committee, and has led technical reviews for major infrastructure and development projects valued at up to £15 billion. He works across energy, infrastructure, transport, industry and the built environment, supporting clients in complex regulatory and dispute contexts.

He holds a doctorate in local air quality management and climate change and is a Member of the Institution of Environmental Scientists and the Institution of Air Quality Management.

Darren Mullins is a Certified Computer Examiner with over 20 years’ experience in digital forensics, cybercrime and complex investigations. He has provided expert testimony in litigation and arbitration across Europe and the Middle East on matters with disputed values of up to $9 billion.

Darren specialises in fraud, financial crime, cyber incidents, electronic discovery and data analytics, with particular expertise in AI‑enhanced document review and defensible AI adoption. Formerly of Deloitte, EY and KPMG, he now leads AI‑driven investigative capabilities at HKA, embedding audited, reproducible workflows aligned with disclosure and expert‑evidence obligations.