He is accused of purchasing eight grams of cocaine between June and July of 2018 and attempting to obtain another gram in May 2018.
Lehtera, 31, issued a statement through the Flyers Monday.
"As I have maintained from the outset, these charges against me are false and I will clear my name," he said. "I will have no further comment on the matter until that time."
The Finnish newspaper Aamulehti reported that prosecutors are seeking a five-month suspended sentence for Lehtera. He was not required to be in court in Tampere, Finland, on Monday.
According to the report, during a wiretap used in an investigation of a large cocaine ring, two suspects were were in contact with Lehtera's cellphone.
Lehtera is not accused of being involved in the drug ring beyond buying and possessing cocaine. Some of the more than 20 defendants in the case face much stiffer penalties for importing drugs into Finland and selling them.
After a September report out of Finland said that Lehtera was questioned by police regarding a suspected drug ring, the NHL said that it "will be investigating the situation."
The Flyers acquired Lehtera in 2017 in the trade that sent Brayden Schenn to the Blues. His point totals have decreased in each of his four seasons in the league -- from 44 in his rookie year to eight last season. He has been a healthy scratch the past six games for the Flyers.
Lehtera is in the final season of a contract that carries a $4.7 million cap hit.