Apple users reportedly had no prior knowledge that their Siri recordings were listened to.

As contractors in the Irish city of Cork listened to over 1,000 Siri recordings per shift before Apple suspended the programme last month, they regularly heard drug deals, sensitive business deals and even recordings of people having sex picked up by Apple's digital assistant, a media report said.

The contractors had the job of listening to and grading recordings by Apple's virtual assistant Siri, the Irish Examiner reported last week, citing a former employee.

The employee said that the details of each Siri user were kept anonymous.

"They (the recordings) were about a few seconds long, occasionally we would hear personal data or snippets of conversations but mostly it would be Siri commands," the employee was quoted as saying.

Contractors working for Globetech, a Cork-based firm, regularly listened to more than 1,000 recordings from Siri each shift, according to the former employee.

These details were revealed after a whistleblower last month told the Guardian that Apple contractors worldwide regularly heard medical information, drug deals, sensitive business deals and recordings of people having sex picked up by Siri, the report claimed.

Apple users reportedly had no prior knowledge that their Siri recordings were listened to.

After details of the practice came to light, Apple suspended transcription and grading work on Siri recordings last month.

"Apple is committed to customer privacy and made the decision to suspend Siri grading while we conduct a thorough review of our processes.

"We're working closely with our partners as we do this to ensure the best possible outcome for our suppliers, their employees and our customers around the world," a spokesperson for Apple was quoted as saying by the Irish Examiner.

"While we conduct a thorough review, we are suspending Siri grading globally," it added.

The reports last month raised concerns as a former contractor at the iPhone maker claimed that Siri interactions are sent to workers who listen to the recordings and are asked to grade it for a variety of factors.