Germany’s foreign intelligence service BND spied on media e-mails, faxes and phone calls, including more than a dozen BBC numbers in London and Afghanistan, Spiegel news reported.
The surveillance, which began in 1999, also extended to Reuters news agency and the New York Times, it is alleged.
“We are disappointed to hear these claims,” a BBC spokesperson said.
“The BBC’s mission is to bring accurate news and information to people around the world, and our journalists should be able to operate freely and safely, with full protection for their sources. We call upon all governments to respect the operation of a free press.”
The BBC has approached the BND about the allegations, but has so far not received a response.
Spiegel reports that at least 50 numbers used by international journalists were monitored by the BND.
The respected German news organisation plans to release more details about the alleged spying on Saturday.
It has seen documents from a German parliament (Bundestag) inquiry into the BND’s role in US-led mass surveillance.
US whistleblower Edward Snowden revealed the global scale of surveillance by the National Security Agency (NSA) which, he said, was assisted by the BND and the UK spy agency GCHQ.