Story highlights Robert Alan Black traveled to Abu Dhabi to speak at a creativity conference

He's detained for taking "a picture of something he shouldn't have," friend says

Spokeswoman: U.S. Embassy is "providing all possible consular assistance"

Family asks UAE officials to release Black, says "any violation is unintended"

An American man -- in the United Arab Emirates to speak at an international creativity conference -- has been detained in that Middle Eastern nation for allegedly taking a photo in a forbidden area, a family spokeswoman told CNN.

Robert Alan Black is being held in Abu Dhuabi's Al Wathba prison, said Rosemary Rein, the family spokeswoman, one of Black's longtime friends and a fellow speaker at the "Creative Thinkers" conference in the UAE capital.

"We know from Dr. Black that he took a picture of something he shouldn't have and that it was stupid," said Rein, who did not know what Black photographed, where or when.

A former architect, Black often takes photos of buildings, according to Rein. Doing so is prohibited in some parts of the United Arab Emirates, particularly in and around government buildings, embassies, military facilities and other places that are considered sensitive.

The family isn't aware of any charges filed against Black. Neither the local police or prosecutor's office have commented on his case, as is customary for similar arrests.

When asked Friday about Black's case, State Department spokeswoman Jen Psaki said that the U.S. government knew of the reports but she didn't offer details.

"We take our obligation to assist U.S. citizens overseas seriously," Psaki said. "The U.S. Embassy in Abu Dhabi is providing all possible consular assistance."

The 70-year-old Black characterizes himself as an architect, cartoonist, graphic designer, professor and creativity consultant on his website . He has given presentations at more more than 150 creativity conferences on six continents since 1978, not to mention authoring more than 600 articles and the book, "Broken Crayons: Break Your Crayons and Draw Outside the Lines."

Rein said that Black's next stop, after the Abu Dhabi conference, was supposed to be Malaysia. But after noticing he hadn't posted to social media, she touched base with common acquaintances and learned that he'd never made it to Asia.

Black's family has spoken to him twice since his detention, after a family member of a fellow inmate let him borrow a phone, Rein said. He told his daughter that guards there were treating him fairly and that he had access to his diabetes medication.

"He was so apologetic and just wanted to come home," Rein said.

Rein said that U.S. Embassy officials are working to get Black a phone card, and that his family is trying to hire a local attorney and raise money for his defense.

The family is also writing a letter to the UAE government, saying "it is our sincere hope that we can talk to officials and bring him home without any further legal proceedings," Rein told CNN.

"We respect regulations, and any violation is unintended," Rein said, citing the family's message. "We truly believe, if you see his profile and his track record as a consummate volunteer around the world, that any mistake that did happen was without any intent to disrespect the culture or the law."