The Morobe Provincial Health Authority said the workshop took place on July 27 and 28. The man has only mild symptoms that are improving while he remains in isolation.
The other 74 participants are in isolation while they await screening.
"No other workshop participants are displaying symptoms. All workshop participants were wearing facemasks and used hand sanitisers, including the COVID-19 case.
"The management of the workshop venue, the Lae International Hotel and hotels in Lae where the workshop participants have been staying (Huon Gulf, Morobe Hotel, Value Inn and Lae Travelers Inn) have all been contacted and staff will be screened as appropriate by health authorities.
"They are currently low risk because they did not spend long periods of time in the room with participants and all the participants were wearing facemasks," Morobe PHA said.
The Morobe PHA adds that a rapid response team has begun tracing and testing. An isolation facility has been prepared at 11 Mile with the people who attended the workshop being accommodated there.