Healthcare group Saolta is investigating a possible data breach at University Hospital Galway.
A number of patients had raised concerns after receiving a letter in the post from an organisation calling itself The Anglo American Lottery.
The scam letter, which was posted to people's home address, informs recipients that they have won a significant prize in the 'Hospital Sick Patient Lottery Draw' as conducted by the 'World Health Concern Charity Org'.
It says that winners were picked anonymously through a "private ballot system of the data of all sick patients admitted in the wards all around Europe".
People who receive the letter are told that the "data generated winning record" showed that they were admitted to a ward in University Hospital Galway (UHG).
Winners are advised to keep the news confidential until the claim has been processed and the money is transferred into their bank account in order to avoid double claims and "unwarranted abuse of this program by other participants".
They are also told to send the lottery their date of birth in order to ensure they are the rightful winner.
The letter advises that all prizes must be claimed within a few days, otherwise the money will be refunded back into the draw,
A questionnaire was attached asking for personal details so that the organisation could "ensure we are paying the right winner".
Contact details at the end of the letter provided the website www.internationallottery.org and a phone number which, when called, rang out and did not provide the organisation's name in a voicemail message.
Darragh Kelly, who was a recipient of the mail, said the possible data breach of his personal details from UHG was "totally unacceptable".
"I am very upset and worried about this as I am sure anyone that received this letter is," he said.
He said "alarm bells" went off when he noticed his address had been spelled incorrectly.
Mr Kelly said he had contacted the hospital and learned that two elderly patients had also raised their concerns about the scam.
He was told the hospital is investigating where the breach originated from, a process which could take several weeks.
Mr Kelly also informed the Data Protection Commission about the issue and has lodged a report with them.
Saolta, the healthcare group which comprises of six hospitals in the west and north west of the country including UHG, said the issue is being investigated.
A spokesperson said a number of patients who recently attended the hospital have notified management that they received the letter in the post from The Anglo American Lottery.
They said that they have followed up with patients and the Data Protection Commissioner has been advised.
"The hospital would like to strongly stress to patients and their families that it has absolutely no association with or knowledge of this company," the spokesperson said.
A spokesperson for the Data Protection Commission confirmed they have “received a breach notification and are seeking further information”.
Saolta is urging patients not to reply to the letter with any personal details and forward a copy of it to the hospital by post to, Information Services Manager, University Hospital Galway, Newcastle Road, Galway, H91 YR71 or email Information.firstname.lastname@example.org.