Blake Phillips, who no longer works at the radio station, made the shocking allegations via a detailed blog post on Monday afternoon.
Phillips, who was the senior video producer at the station, reported the case to police at the time but decided not to pursue legal action.
In his post, Phillips reveals that he has met with detectives to reopen his case.
'Detectives from Sydney City Police Area Command are conducting inquiries into a reported sexual assault that allegedly occurred in August 2013,' A NSW police spokesperson told news.com.au.
Writing online, Phillips wrote: 'I am exploring all options of the law to set precedence for others who may find themselves somewhere in a similar lonely dark journey that can take years to recover from, if at all.'
The former 2Day FM video producer reveals he regrets not pursuing legal action in 2013, saying that he chose to 'deal with it off the public record' through Southern Cross Austereo’s HR department as he feared media scrutiny and public backlash.
He wrote, 'I had no idea or capacity to research my rights at the time and now it makes me feel sick knowing how much better it could have been.'
Blake reveals that the 2Day FM staff member accused 'stood down' and was 'walked out of the building.'
Southern Cross Austereo said in a statement to news.com.au that it 'takes incidents of this nature very seriously and any inappropriate behaviour by members of our staff to be completely unacceptable'.
'In 2013, on becoming aware of the incident, SCA acted promptly by investigating and terminating the employment of the (staff member).
'SCA supported Blake including assisting him with his conversations with the police and providing him with extensive counseling. This support was ongoing for the duration of his remaining two and a half year employment, including his request to be relocated to another office within the company.'
Phillips claims he was left traumatised by the incident.
'Navigating years of suicide, medicating with self and prescription substances, amongst endless varieties of therapy to combat relentless anxious madness is no longer a worthwhile battle,' he wrote online.
Mel Greig, a radio and television personality who worked at 2Day FM with Blake, has spoken out in support of Phillips, claiming that the event was 'whispered' about in the industry.
Sharing a post, Greig writes: 'The truth is the radio industry has whispered about the alleged attack for years, someone's tragic encounter has been workplace gossip.
'No one currently working in the industry has come out and supported him and there are so many big names that know about it.'
Greig finished her post with '#istandwithblake'
Former radio star Adam Richard has also come forward to slam the radio industry for its silence on the matter, tweeting: 'As one of the 'heavyweights' mentioned [in media reports as supporting Blake], we all have one thing in common: we don't work in radio right now. The silence from those still in the fold is deafening, and damning of the entire industry.'
If you or someone you know is in need of crisis or suicide prevention support, call Lifeline on 13 11 14 or visit lifeline.org.au/gethelp.