FOXBOROUGH. Mass. — New England Patriots receiver Stefon Diggs participated in his first offseason practice since video appeared on social media showing him passing what appeared to be a bag of pink crystals to women on a boat.

Diggs attended Monday’s voluntary practice session six days after videos were posted online of him chatting with three women before producing the substance. It wasn’t clear what the substance was. An NFL spokesman said the league would not comment, and Patriots coach Mike Vrabel said the team would handle the matter internally.

Diggs, 31, has attended multiple events this offseason with hip-hop star Cardi B — including the Met Gala and a Boston Celtics-New York Knicks playoff game.

The Patriots have two remaining optional workouts on Tuesday and Thursday as part of the spring organized team activity window allotted to each NFL team. Both of those remaining sessions are closed to the media. The players have a mandatory three-day minicamp beginning on June 9.

Diggs signed with the Patriots this offseason, getting a three-year, $69 million deal that guarantees him $26 million. The four-time Pro Bowl selection had six straight 1,000-yard receiving seasons for the Vikings and Bills before he was traded from Buffalo to Houston last spring.