The US Food and Drug Administration has warned Tyco International's Healthcare unit over its failure to set up proper procedures to verify its products, according to a letter made public today.

An FDA inspection of Tyco's plant in Galway - which makes ventilators, oxygen therapy products and other devices - also found a lack of procedures to hand complaints in a timely fashion and take corrective actions, the warning letter said.

An earlier response from the firm was 'inadequate,' the FDA added.

The FDA said that findings from the inspection, which was concluded in March, violated the agency's manufacturing and quality regulations.

Tyco Healthcare Vice President of Regulatory Affairs David Olson responded to the agency in March, May and June, but the FDA said the responses did not include enough specifics about proposed new procedures.

The FDA said it had also requested an update on pending complaint investigations and more details on the firm's new customer complaints procedures.