More than 500 women will have to have their smear tests repeated after it was found a nurse who carried them out may not have been qualified to do so.

The 536 women from Sittingbourne and Sheppey are being sent letters inviting them to have another cervical screening smear test at their local GP surgeries.

A spokesman for the Eastern and Coastal Kent NHS Trust said it was just a precautionary measure following the identification of an issue with the qualifications of a nurse to take the tests. The tests were performed in GP surgeries.

She said: "The nurse is no longer taking cervical smear tests and will retake the cervical screening training course. The GP practices have been asked to undertake a full investigation and report the findings to the PCT.

"Lessons learned will be shared with the wider health community to ensure the likelihood of this type of incident occurring in the future is reduced and that the risk to future patients is diminished."

Dr John Rodriguez, assistant director of Public Health and Screening Lead for Kent and Medway, said: "Although it is most likely the tests were performed to a satisfactory standard, we cannot be sufficiently certain, and therefore this recall exercise is a precautionary measure."

He said as a result of this review, the Trust had put in more robust training procedures in place.

Extra smear test clinics have been arranged to ensure the re-tests can be carried out as quickly as possible.

The NHS Eastern and Coastal Kent Patient Advice and Liaison Service (PALS) may be contacted on freephone 0800 085 6606 to answer questions from any concerned women.