The alleged attack on a 21-year-old woman took place in Edinburgh’s Canongate area in the early hours of January 1.
A 25 year-old male was arrested in connection with the incident on Monday and a report has been sent to the procurator fiscal.
He has since been released from custody as the investigation continues.
A spokesman for the Crown Office said: “The Procurator Fiscal at Edinburgh received a report concerning a 25-year-old male in connection with an alleged incident on 1 January 2014.
“After full and careful consideration of the facts and circumstances of the report, the accused was liberated from custody pending further investigation and did not appear in court.”