The BBC said problems with BBC Persian on the Hot Bird satellite began on Tuesday morning.
Eutelsat, owner of the satellite, confirmed the location of the source of the jamming as being in Iran, the BBC said.
“The BBC and Eutelsat condemn this deliberate interference that is clearly contrary to international conventions for the use of satellites,” the BBC said in a statement.
BBC Persian TV continues to stream live online and on three other satellites.
The BBC said Persian television has suffered a number of similar attempts to interfere with its signal intermittently since it was launched in 2009.
In February, the BBC accused Iran of interfering with its television coverage of protests in Egypt. (Created by Clare. Kane)