A Brazilian priest known for delivering sermons disapproving of kissing and sex outside marriage has been suspended for sending a nude selfie to an apparent mistress.

"Father Alfredo Rosa Borges has been suspended from his duties," and faces ex-communication, a diocesan spokesman at Campos de Goytacazes, a northern town in Rio state told AFP on Tuesday.

Borges is seen posing naked in front of a mirror holding his mobile phone in pictures posted last week via smartphone service Whatsapp which have since appeared in online media.

Rio daily O Dia reported he had admitted sending suggestive messages to a woman who later posted them but denied having an intimate relationship with her.

"An investigation has been opened but the photo comprises a transgression for the Church," the bishop of Campos, Roberto Francisco, told O Dia.

Worshippers at Borges' Santo Antonio church reported he had first insisted the picture was fake but then conceded it was him and explained that "we are all sinners".

Borges authors a blog where he expresses conservative views on social issues, dubbing kissing a "grave sin" and sexual liaisons as a "serious moral disorder as normally it leaves aside and abandons the procreative aspect".