WASHINGTON - The family of an American detained by the Democratic People's Republic of Korea (DPRK) has released an open letter to plead for his release, media reports said on Wednesday.

"We write to plead for the humanitarian release of Eddie Yong Su Jun, our loving father and husband, who has been detained by the DPRK since November 2010," said the letter, according to the CNN website.

"We have recently received worrisome news that he has been hospitalized, and we are grateful to the DPRK for supplying him with medical attention. However, we remain extremely concerned about his sensitive health condition," the letter said.

DPRK has confirmed the arrest of Jun for "committing a crime against (DPRK) after entering it." Earlier this month, the US State Department also confirmed an American citizen has been detained by the DPRK, calling for his release "on humanitarian grounds."

Former US President Jimmy Carter arrived in Pyongyang on Tuesday, one of whose missions could be securing the release of this American.

In August last year, Carter flew to the DPRK on a private trip, bringing Mahli Gomes, a 30-year-old from Boston who was detained by the DPRK for illegal entry into the country, back to the United States.