Gardaí are investigating a postman in relation to the suspected theft of up to 30,000 letters and parcels over the last year.
Two garda vans had to be used to remove the letters, packages and shredded paper from the home of the An Post employee in Dublin.
Gardaí obtained a search warrant last week on foot of their investigations into a substantial amount of missing post in a suburb of south Dublin.
It is suspected that thousands of items of post were taken, possibly up to 30,000 in total.
Gardaí are investigating if the alleged theft has been going on for some time. It is understood that some post retrieved was dated over a year ago.
Part of the investigation is determining whether or not any cash or valuable items were in the post, with letters addressed to charities, businesses, and clubs being closely examined.
The investigation team has the job of sifting through all the evidence and cataloguing it. They will also try and examine any shredded letters and envelopes seized.
A shredding machine was taken from the man’s home for examination.
Post that isn't being retained as evidence has been returned to An Post for forwarding to the recipients.
It is understood the postman has been working in the company for a number of years.
A Garda statement said: “Gardaí are investigating a report of alleged theft of a volume of material from a national service provider, involving a member of staff.
An Post said it is assisting gardaí and that an investigation is also underway.
“The An Post / Garda investigation is ongoing so we cannot make any further comment about any aspect of this matter at this time,” An Post said in a statement.
It said it had sent out the following letter to affected customers: “We sincerely apologise that standard mail addressed to you was not delivered in a timely fashion due to a serious service failure which is subject to an ongoing investigation by An Post and An Garda Síochána.
“Please find enclosed mail for your address which has been located during the course of the investigation.
“While the investigation is ongoing, we are unable to provide any further information. However, please rest assured that the delivery of your mail, the full resolution of this unfortunate matter and the resumption of our top-quality delivery service remain our highest priorities.”
It said it has established a dedicated phone line at (01) 705 8600 for anyone with concerns.
Newly elected Fianna Fáil TD for Dublin South Central, Catherine Ardagh, highlighted the issue recently when she posted a video online, prompting concerned calls from local people.