Justin Bieber; Anne Frank
Kevin Mazur/WireImage; Anne Frank House/Getty
There's a name for the inner circle of followers who know every song, every lyric and every little move Justin Bieber
And if Anne Frank had not died at the age of 15 living inside a concentration camp in Nazi-occupied Germany, the pop star says he hopes she would have joined the ranks of those very fans.
In a controversial note he left in the guestbook at Amsterdam's Anne Frank House, he wrote (according to the museum's Facebook page
), "Truly inspiring to be able to come here. Anne was a great girl. Hopefully she would have been a belieber."
However, there is a simple explanation for the comment, a source tells PEOPLE.
"Justin took the time to visit the museum after reading Anne Frank's diaries – he wanted to follow-up by visiting her house. Someone told Justin during the tour that Anne was very into pop culture and probably would've been a fan of Justin," the source says.
"It's sad that people are so quick to criticize without understanding the context with which he made those comments."
Bieber, 19, visited the museum Friday with a group of friends and guards between gigs in Antwerp, Belgium, and a Saturday stop in Arnhem, Netherlands amid a rocky European tour
"He was very interested in her story," museum spokeswoman Maatje Mostart tells the New York Daily News
. "We hope a lot of his fans will want to read about Anne Frank."
The museum is using the increased attention to educate a larger audience about Frank, who died in March 1945 of typhus but continues to live on through her diary detailing her life in hiding during the Holocaust.
"We really think that it's great that a 19-year-old person wants to know who Anne Frank was and know more about her," Mostart notes.
Reporting by KEVIN O'DONNELL