The Canadian company said an employee was fatally pinned in the 17-level underground development after an underground ore cart derailed.
The company said it was working with relevant authorities to establish the exact cause of the accident, with Prestea mining activities suspended Wednesday.
"This is a tragic accident and all of our thoughts are with our colleague, his loved ones and the wider team at Prestea. The accident will be investigated fully and we will redouble our efforts to make sure that we prevent anything of this nature from happening in the future," said CEO Andrew Wray.
The company has maintained 2020 gold production guidance at 195,000-210,000oz at a cash operating cost of US$790-$850/oz.