Durham police say a lengthy investigation into a debit and credit card fraud ring has resulted in four arrests.

Police say they have identified over 48 hundred debit and credit card numbers belonging to victims across Ontario.

Investigators say legitimate debit card terminal pin pads were stolen and a decoy pad was left in its place.

The original pad was then tampered with to secretly record debit card and PIN numbers and then returned to its original location.

The suspects would then collect the data via a sophisticated wireless connection and use it to manufacture forged debit cards.