Concern around the member, who is based in north Dublin, was raised at the weekly Fine Gael parliamentary party meeting in Leinster House last night.
The man has called women obscene names on Twitter and used bad language and slurs against women both within the party and outside it on social media, particularly around the topic of abortion.
Ms O’Connell told colleagues she had made a formal complaint to party headquarters and that a letter had been sent to general secretary Tom Curran.
Ms O’Connell voiced her concern about “online abuse” by the Fine Gael official and circulated a five-page printout of tweets by the man.
These included nasty remarks made to women, calling female politicians “bitches” on several occasions.
The person has also dubbed individuals “stupid” over their views on the Eighth Amendment.
It is understood that some of the tweets had been directed at Ms O’Connell.
Ms O’Connell asked her colleagues for support with her complaint at the meeting.
The Fine Gael member, a non-elected official, is based in Dublin and has worked with the party for many years. The person also holds an important role in the party.
Another female Fine Gael politician spoke of her concern about the online abuse by the party figure.
Stephanie Regan, who ran for the Fine Gael party in the Dublin Bay North constituency in last year’s general election, said: “I don’t think he has respect for women. I think it certainly has to be addressed by the party.”
Ms Regan, who campaigns against bullying and harassment in the workplace, said she had made contact with the person last year over the contents of his tweets.
“I would have spoken out to him over a year ago — I was thinking, ‘Does he realise that in every second tweet he is using the work bitch?’ I think that he has an unfortunate lack of awareness about how he comes across and maybe how he feels about women.”
Calls were not returned to the Irish Examiner last night by the official in question.
A Fine Gael party spokesman last night declined to comment on the issue.