To use the VoicePay TV service, businesses place a logo, free phone number and unique product code in video adverts.

If customers want to buy the product advertised they call the phone number and authorise the transaction by 'signing' for purchase with their voice.

To use the service customers have to open a VoicePay account, creating their signature using voice biometrics as well as their purchasing history, trends and location patterns. The vendor says the signature is unique and cannot be imitated - even by recording someone's voice.

A nominated credit or debit card is linked to the customer's voice signature and used to make payments whenever they call and authorise a purchase. The vendor says that because customers do not need to hand over their card details every time they make a purchase the risk of phishing and identity theft is reduced.

Advertisers benefit because there is a much shorter gap in the purchasing lifecycle between grabbing a customer's attention and selling them the product. They no longer need to rely on the customer to remember their advert or product before visiting the Web site at a later date.

In addition, businesses can see a measurable return on investment from advertising - all incoming calls from customers can be traced back to product codes from exact adverts and locations, making it possible to monitor the effectiveness of campaigns.

Nick Ogden, founder, Voice Commerce Group, says: "Our voice signatures overcome the challenges of using other payment tokens or mechanisms because they do not require additional devices, passwords or pins and, after all, consumers now carry their own voices as well as their mobile phone wherever they go."

The VoicePay network currently covers over 50 countries and is fully integrated with Visa and MasterCard.