The 20-year-old woman got into a taxi when she left a well-known nightclub in Dublin city centre at 2am on Tuesday to bring her to Dublin City University accommodation in Glasnevin, north Dublin.
The taxi driver, from south-west Dublin, took a route via Phoenix Park, stopping near the Wellington Monument. The woman claims the man raped her, while he maintains that the sex was consensual.
He gave the woman his phone number then dropped her back to DCU. The woman immediately alerted security staff on arrival, who contacted gardaí.
Gardaí contacted the man using the number he gave and arranged to meet him. They took a statement from him and seized his car for forensic examination.
The man, who no longer lives at home, has not yet been arrested.
Detectives are likely to wait until they have gathered all relevant evidence before arresting him.
This includes medical examinations contacted at the sexual assault treatment unit in the Rotunda Hospital. They may show whether or not force was used, which would substantiate the allegations.
The investigation team is also gathering CCTV footage from inside and outside Copper Face Jacks nightclub on Harcourt St. They hope this will show the physical condition of the woman and where she sat in the taxi. They will also speak to staff, particularly security staff at the door, who might have seen her get into the taxi.
Gardaí will examine her statement in detail. They will also wait and see if the technical examination of the taxi reveals evidence.
Senior officers said that while it was “unusual” for anyone who committed a rape to give the victim their phone number, it was not unheard of. In situations where an attacker is delusional, or genuinely, if wrongly, believes sex was consensual, they could do so.
One source said it could be the case that the matter will only be determined in the courts, where a jury will have to weigh up the testimony of both parties, along with any other relevant evidence.
Denise McCarthy, deputy president of Union of Students in Ireland said: “Having sex with someone who cannot consent, because they are too drunk or are in fear, is rape.”
Fiona Neary, director of the Rape Crisis Network Ireland, said: “While all criminal activity and/or threat of criminal activity should be reported to the gardaí it is important to note that conduct that is inappropriate but not necessarily criminal should also be reported.”