(CNN) -- An American couple that went missing on a bike trek through Peru has been spotted "safe and sound," the South American country's top tourism official said Tuesday.
Jamie Neal and Garrett Hand are heading upstream in a small boat on a jungle river, said Jose Luis Silva, Peru's minister of tourism and commerce.
"They're currently in a remote, paradise-like region of the Peruvian Amazon, which is difficult to access," he told CNN.
But even as authorities trumpeted the news, Hand's mother said in a statement that she won't believe it until she hears directly from her son.
"We have not heard from them since January 25, nor have they accessed bank accounts since that time," mother Francine Fitzgerald said. "We have only the worst to consider as to why."
The couple, who hail from the San Francisco area, left last November and began a series of social media posts chronicling the trip of their dreams -- a four-month bike adventure through South America.
"Will be riding my bike in other countries and out of contact for 4 months!" Neal wrote in a November Facebook post before flying with Hand to Buenos Aires, Argentina.
But for weeks, the couple shared photos online from their trek through Argentina, Chile and Peru, showing themselves posing beside their bikes on remote mountain roads, camping out in tents and smiling at the beach.
In late January, however, their Internet postings stopped and calls to their cell phones went unanswered. Family members say no one has been able to get in touch with them since then.
Fitzgerald said both the U.S. Embassy in Peru and the country's interior ministry have called to say that Neal and Hand were spotted.
But that's not enough, she said.
"Let me reiterate, until we have PROOF OF LIFE, we cannot celebrate these rumors and sightings," she wrote on a Facebook page set up to facilitate a search for the couple. "Proof of life is my son's voice on the phone and a picture of him holding the missing poster."
Silva told CNN that the tourism ministry learned of the couple's location from police, who received a report from a clinic in the town of Angoteros after sending out a nationwide alert about the missing couple.
The ministry will send a hydroplane tomorrow to shoot video of the couple and provide proof they're doing OK, he said.
"They have no idea of the commotion they have caused in the media," he said, "because they simply can't communicate with family from where they currently are."
Neal and Hand, both 25, according to a family flyer, were last seen in Lima, the Peruvian capital. But some of the areas they planned to visit are out of cell phone and Internet reach.
The Peruvian National Police earlier told CNN that the manager of a hostel in Pucallpa, where the couple stayed, confirmed to a police investigator they reached the jungle city in early February.
The manager of Arco Iris Amazonica, a small hotel in the rain forest city of Iquitos, told police the couple stayed there on February 16 and told him they planned to travel to the town of Naplo, a 15-day trek.
Peru is known for the Inca ruins of Machu Picchu, located in the Cusco region, which attract hundreds of thousands of international travelers each year.
Two weeks ago, the U.S. Embassy in Lima issued a security message warning Americans of "a potential kidnapping threat in the Cusco area."
"The Embassy has received information that members of a criminal organization may be planning to kidnap U.S. citizen tourists in the Cusco and Machu Picchu area," the message said.
But it also clarified that "thousands of U.S. citizens routinely travel to the Cusco region without undue incident. The U.S. Embassy remains confident of the Peruvian government's efforts to ensure the safety of all tourists in the region."
Peru's tourism minister said Tuesday that he was "deeply concerned" about the negative impact of reports of the missing American couple.
The reason the couple has been out of touch for so long has nothing to do with any crime, he said.
"These two young people have fallen in love with Peru," Silva said. "They have visited off-the-beaten-path places and it seems like they're having a blast -- so much so that they have forgotten to communicate with their families."
CNN's Catherine E. Shoichet and Tom Watkins contributed to this report.