The Allen County coroner's office confirmed to CNN that he had died of natural causes.
"The Purdue basketball family is deeply saddened and devastated at the loss of Caleb Swanigan," head coach Matt Painter said in a statement on the team's website.
"Caleb was a very thoughtful individual and a gentle soul who excelled both on and off the court. He made a huge difference in everyone's lives that he touched and he will be greatly missed."
"During his NBA career, Swanigan worked extensively with Portland-area youth and Food Corps to promote healthy eating habits in schools and eliminate child hunger," Purdue's statement added.
In his sophomore 2016-17 season, Swanigan averaged 18.5 points per game, 12.5 total rebounds and 3.1 assists per game for Purdue, helping it to the Sweet 16 of the NCAA men's basketball championship.
For his efforts, the forward won Big Ten Player of the Year and was named a consensus First Team All-American.
Swanigan made 75 appearances and four starts during his three seasons in the NBA after being drafted by the Portland Trail Blazers as the No. 26 overall pick in 2017. He also played for the Sacramento Kings.
"We are heartbroken by the passing of former Trail Blazers player Caleb Swanigan. Our thoughts are with Caleb's family, friends and all who loved him. Rest In Peace, Biggie," Portland said on Twitter.
In an interview with ESPN in 2017. Swanigan spoke about his difficulties controlling his weight and of a childhood without reliable access to housing or food.