Updated

Nationwide Series driver Nelson Piquet Jr. has been fined $10,000, placed on indefinite probation and ordered to participate in sensitivity training for using a homophobic slur on social media last week.

NASCAR announced the penalty on Tuesday, stating, "On September 25, Piquet violated Sections 7-5 (Code of Conduct) and 12-1 (actions detrimental to stock car racing) of the 2013 NASCAR rule book."

Piquet wrote on Instagram a three-letter word while commenting on a photo of fellow Nationwide competitor Parker Kligerman. His comment has since been deleted.

"Nelson Piquet Jr. recently communicated an offensive and derogatory term that cannot be tolerated in our sport," said Steve O'Donnell, NASCAR senior vice president of racing operations. "NASCAR's Code of Conduct explicitly spells out in the 2013 rule book our position regarding the use of disparaging terms. We expect our entire industry to abide by this Code."

Piquet has apologized for the incident.

"I sincerely apologize to everyone for my poor choice of words last week," Piquet said in a statement. "I did not mean to hurt or offend anyone. This has been a cultural learning experience that will make me a more sensitive person moving forward."

Piquet, a former Formula One competitor, is in his rookie season in Nationwide. He drives the No. 30 Chevrolet for Turner Scott Motorsports.

"We have spoken to Nelson about his insensitive comment and he understands that such remarks will not be tolerated at Turner Scott Motorsports," the team said in a statement. "TSM expects those associated with the team to uphold professional standards that we can all be proud of. Nelson has assured the team that he has learned his lesson and he knows what it means to represent TSM."