Cobwebs Technologies scanned social media platforms under a contract that ran for four years up until April, with the Ministry of Business, Innovation and Employment (MBIE).
All the data gathered was stored in Australia in cloud computing space rented from Microsoft.
The ministry used the data, but said it gave Cobwebs no authorisation to access it.
MBIE also released a letter dated 12 August - several days after an RNZ request - from Cobwebs, confirming it did not access the data.
"We confirm that following the conclusion of the contract, the cloud service has been completely erased and is no longer available to MBIE," said the letter from the firm that was set up in Israel, and is now US-owned.
"All associated information has been securely and thoroughly removed."
The ministry said this was standard practice.
"No further steps to 'return' information have been taken, as the information has been removed."
The ministry has been considering how to replace the Cobwebs service, which it says it acquired and only ever used to deter mass arrivals by boat people.