Salgueiro Vicente, 35, a journalist for Rádio da Ecclesia – Catholic Broadcaster of Angola, was found dead inside his home, in Luanda, in the early hours of Wednesday.
A familiar source admitted it was "sudden death".
The journalist's corpse is in the Morgue Central de Luanda.
The SIC, which expressed its dismay, said in a note that the body "will be submitted to a medico-legal examination for the purpose of determining the real causes of death" of the journalist.
The Angolan journalistic class, particularly colleagues from the editorial staff of Rádio Ecclesia, has expressed sadness and shock at the professional's death.
The bishops of the Episcopal Conference of Angola and São Tomé (CEAST), which owns the Catholic radio, also expressed their dismay.
In a condolence note, the Angolan Journalists Union expresses itself "dismayed by the death of journalist Salgueiro Vicente", referring that the class and Radio Ecclesia "lost one of its most promising journalists, committed to an impartial and plural journalism".
The council of governors of the Southern African Social Communication Institute (MISA-Angola) also expressed its "deep desolation" at the journalist's untimely death.
The Minister of Telecommunications, Information Technologies and Social Communication, Manuel Homem, said that it was with "a great deal of regret" that he learned of the death of Salgueiro Vicente.
"A professional of the Angolan media, placed in the central studios of Rádio Ecclesia, Salgueiro Vicente leaves us the image of an intrepid reporter, editor and announcer, who knew how to fulfill his mission of informing with professionalism and exemplary dedication", reads message of condolences from the ruler.