By Maria Ward-Brennan Consultancy firm McKinsey has been placed under criminal investigation in the US over its role in the country’s Opioid crisis. The elite firm is in the spotlight over its work advising OxyContin creator Purdue Pharma and other drugmakers. Oxycontin-maker Purdue Pharma was reported in 2019 to be making payments between $10bn (£8bn) and $12bn (£9.5bn) to settle more than 2,000 lawsuits over its role in the Opioid crisis. The disgraced manufacturer filed for bankruptcy in 2019 after it admitted that the company would be unable to withstand the mass lawsuits against it. The c…