A HUNTING knife was delivered to murder accused Graham Dwyer's workplace the day before Elaine O'Hara disappeared, the Central Criminal Court heard.
Records showed it was ordered online in Mr Dwyer's name, and brought by courier to his office marked "private and confidential" on August 21, 2012.
Gardai went on to find a hunting knife and a flick knife among files in the architectural firm's basement in early 2014 - after Mr Dwyer sent them a map directing them to it.
The jury in his trial also heard that a query to a tattoo studio about getting a tattoo in "a private area of the body" was apparently sent from an email address containing the same number as that on Mr Dwyer's model plane club membership card.
Mr Dwyer (42), of Kerrymount Close, Foxrock, is pleading not guilty to the murder of Ms O'Hara (36) at Killakee, Rathfarnham on August 22, 2012.
Ms O'Hara, a childcare assistant from Killiney, was last seen alive near Shanganagh Cemetery in Shankill that day.
Her remains were found by a dog walker in undergrowth in the Dublin mountains on September 13, 2013.
The prosecution maintains Mr Dwyer killed her for his own sexual gratification.
Detective Sergeant Peter Woods said he found two knives in a file box in the basement of architect Graham Dwyer's workplace after the accused volunteered the information to gardai through his solicitor.
Det Sgt Woods said on February 17, 2014, he received a phone call from Mr Dwyer's solicitor, Jonathan Dunphy, and an accompanying fax message with a sketch map of the basement at A&D Wejchert Architects, Baggot Street Lower - the accused's workplace.
The map, shown on screens to the jury, was accompanied by a list of "items of interest". It showed a plant room to the right, an area where photographs were stored, a desk and software underneath it. There was also a filing area with an asterisk to draw attention to that.
A plain cardboard magazine- holder-style filing box beside a timber partition was noted.
Det Sgt Woods went with two other officers and spoke to a partner in the firm, Paddy Fletcher, who allowed them access.
They showed him the map and he directed them to the basement area and to where old files were stored.
Det Gda Woods had gloves on his hands and he went to the area indicated on the map.
"I found two knives, one larger than the other," Det Sgt Woods told Sean Guerin SC, prosecuting. "This is the knife I found (in the box). I found it in the leather scabbard in the file box."
He removed the silver-bladed, black-handled knife from its black scabbard and held it up in both hands for the jury to see.
Mr Guerin said it was a Buck Special hunting knife. The smaller knife, also shown to the jury was a flick knife with a lock on it.
Det Sgt Woods said when the Buck knife was found it was not in its original presentation box.
He said the knife cover was in "pretty good condition" with some small marks and scratches, and the knife itself was in good, clean condition.
The second knife was also in good condition and its safety catch in place, he added.
The court was told Mr Dwyer was charged on October 18, 2013, and the book of evidence served on him in January 2014.
Cross-examining Det Sgt Woods, defence barrister Remy Farrell SC said it became apparent from the prosecution evidence that gardai had attached significance to the ordering of a Buck hunting knife by the defendant.
Det Sgt Woods said the fact it was delivered on August 21, 2012, was "hugely significant" for investigators.
Mr Farrell said gardai were also concerned there was originally no sign of the knife, adding that Chief Superintendent Diarmuid O' Sullivan has made a "huge emphasis" on this.
The defence said it was for this that the communication and sketch showing exactly where the knife was being stored was sent to gardai, he added.
Michael Fenlon confirmed a Buck hunting knife was purchased online from his company, Active Hunting Ireland, on August 17, 2012.
The Buck Special 119 knife, which had a laminate handle, cost €100 including shipping. It is sold in a leather sheath and box.
"Please mark private and confidential, Graham," was written in the comments section of the order, Mr Fenlon confirmed.
It was paid for by credit card, with Mr Dwyer's Foxrock home as the billing address and his workplace as the mailing address.
Earlier in the day's evidence, Christof Hylinski of Hydraulic Tattoos, South King Street, Dublin, said his company sent an email about a tattoo on April 28, 2011, to firstname.lastname@example.org.
The content of the email was that it was "no problem to get a tattoo like this" and the price would be €100.
The mail said "we have a separate area in our studio for jobs like this one."
Mr Hylinski had no memory of sending the mail but he found it on his computer system, printed a copy and gave it to the gardai
Asked by Mr Guerin to explain the reference to jobs like this one, Mr Hylinski said he meant "to make it more private".
"It is a job on a more private area of the body," he added.
Mr Guerin showed a membership card for Roundwood Eagles model plane flying club to the jury and asked Mr Hylinski to confirm the number on the card was the same as the number in the recipient's email address.
The card was shown on screens to the court and Mr Justice Tony Hunt said "it seems apparent".
The trial continues before the judge and jury.