THOUSANDS of packs of an over-the-counter painkiller could have higher-strength tablets inside that are only available on prescription, a Government health watchdog has warned.

Some packs in a 40,000-strong batch of co-codamol 8mg/500mg strength tablets manufactured by Wockhardt UK Ltd have been found to contain the higher strength co-codamol 30mg/500mg product, the Medicines and Healthcare products Regulatory Agency (MHRA) said.

It is believed to be down to a manufacturing error.

Ian Holloway, MHRA head of defective medicines report centre, said: "If you think you have taken the wrong strength tablet, and in the unlikely event you feel unwell, speak to your pharmacist or GP."