Rev Simon Bone wrote to the Bishop of Truro resigning as priest in charge.
"I am deeply sorry for the hurt and upset that I have caused to everyone, but especially to my family," he wrote.
A spokesperson for the Diocese of Truro confirmed Father Bone's resignation and said: "The diocese takes all matters of professional and personal conduct seriously, and will take appropriate action as necessary and depending on individual circumstances."
According to a profile on the website for the Eight Saints churches, which is comprised of St Day, St Petroc, St Paul, St Piran, St Stythians, St John, St Feock and St Wenappa, Rev Bone is married with one daughter.
He added: "I trained for the priesthood at Ripon College, Cuddesdon and was ordained Deacon at Petertide 2009. I served my title as an Assistant Curate at St Michael's Church, Newquay and I am currently the priest in charge of the 8 Saints' Cluster and WAY2 internship.
"I am a training incumbent for a curate, a member of the management board for the St Petrocs Society, the assistant rural link officer for the Diocese, a chaplain for the fire brigade, a member of Diocesan Synod and the assistant diocesan director of Ordinands."
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