Aviva has dismissed an employee following fears that customer information had been sold to a third party.
The City of London Police's Insurance Fraud Enforcement Department (IFED) has also launched a criminal investigation into the matter.
Aviva said no sensitive personal financial or medical information was accessed or disclosed.
The provider added it has written to affected customers, for the second time in two years in such circumstances, to apologise for any inconvenience caused.
The Insurance Age team examine the most read stories for the week commencing 3 June 2019.Subscribe to our daily newsletter for all the latest news
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- Adrian Brown becomes NED at SSP
- Waite-led Premium Credit takes Howells from Close Brothers and Thomas from RSA