Ireland's largest pharmacy group, LloydsPharmacy has repaid the Health Service Executive €12m for dispensing fess that the company incorrectly charged, RTÉ News has learned.

The irregularities were revealed by RTÉ Investigates last year.

In a further development similar HSE investigations are also ongoing into five other pharmacy chains or branches.

With 94 branches nationwide, LloydsPharmacy is Ireland's leading pharmacy chain.

Last year the RTÉ Investigations Unit revealed irregularities in the level of dispensing fees being claimed by the pharmacy chain from the HSE.

The irregularities centred on phased dispensing fees charged by LloydsPharmacy on its weekly medication management system, MyMed, a modern equivalent of a pill box that segregates drugs into weekly packs for those on large amounts of medication.

There are very limited circumstances under which a pharmacy can claim additional charges for the phased dispensing of drugs but documentation provided to the RTÉ Investigations Unit by a whistleblower last year showed that LloydsPharmacy staff were actively encouraged to widely promote the MyMed system to its customers which generated substantial additional profits for the company.

Each store was provided with monthly targets for the number of customers who had to be converted to the MyMed system and further documentation showed that on repeated occasions LloydsPharmacy customers were provided with a month's supply of their medication in one go despite payment statements from the HSE showing that phased fees were submitted as if the drugs had been dispensed each week.

RTÉ learned that following a HSE investigation LloydsPharmacy has been found to have over-claimed in the region of €12m in dispensing fees.

The sum is believed to have been repaid in full.

While not naming the company, in a statement the HSE said a "satisfactory resolution" had been reached.

A spokesperson for LloydsPharmacy told RTÉ the matter had been "resolved" between the parties.

In a further development, RTÉ has discovered that similar HSE investigations are also ongoing into five other pharmacy chains or branches.

It is understood those investigations are at an advanced stage and could result in further money being paid back to the HSE.