Libyan authorities have acknowledged that they have detained Maryland resident Matthew VanDyke, according to Rep. C.A. Dutch Ruppersberger.
The Libyan government, Ruppersberger said in a statement Tuesday, "will now be held accountable for his welfare and whereabouts."
VanDyke, 31, went to Libya in early March to "witness history," his mother Sharon VanDyke told The Baltimore Sun last month. Sharon VanDyke is a retired schoolteacher who lives in South Baltimore.
She said she last spoke to her son on March 12. The next day, he sent GPS coordinates that placed him near the Libyan city of Brega. But she has not had any contact with him since.
In April, the State Department counted him among several Americans missing in Libya.
At the end of July, Sharon VanDyke said that she knew her son was being held in a prison in Tripoli. She would not divulge details of how she learned of his whereabouts. Ruppersberger has been a vocal supporter in Washington of her attempts to locate and repatriate her son.
"We must continue to use any and all resources here in the U.S. and on the ground in Libya," Ruppersberger said Tuesday. The U.S. must reach out to allies and with operating embassies in Libya, he said, to ask for assistance with the freeing of VanDyke and other Americans.
The Sun previously reported that VanDyke earned a bachelor's degree in political science from the University of Maryland, Baltimore County and a degree in security studies from Georgetown University's School of Foreign Service. He is listed on the Committee to Protect Journalists website as a freelance journalist.
According to his family, VanDyke has traveled extensively in the Middle East and was working on a book about his experiences there. His trip to Libya, which is in the midst of a civil war, is to be the book's final chapter, they said.
"Matthew's mother, Sharon, has never given up hope," Ruppersberger said, "and I will continue to do whatever I can to ensure this story has a happy ending."
Baltimore Sun reporters John Fritze and Mary Gail Hare contributed to this article.