Graham Dwyer's appeal against his conviction for the murder of Elaine O'Hara is due to get underway this morning.
Two days have been set aside to hear his arguments.
It comes a decade after Elaine O’Hara was killed after going missing in August 2012. The 36 year-old's remains were found in the Dublin mountains just over a year later.
Graham Dwyer was found guilty of murdering her following a high-profile trial before the Central Criminal Court seven years ago.
The architect always intended to appeal his conviction, but the reason for such a delay is because his defence team first took a controversial law to court.
It took a long time but they successfully challenged the law that allowed for the indiscriminate retention of mobile phone call records and location data.
This metadata featured heavily in Dwyer’s trial back in 2015 and his successful legal challenge against it will feature in this contested appeal against his conviction.