German business software vendor SAP has issued a warning to customers not to provide confidential information on the phone to people claiming to be company support staff.

"Over the past several weeks, several customers have received calls to provide confidential data such as access codes from groups requesting this information to correct some alleged problems," said SAP spokesman Markus Berner. "We have a policy never to request confidential data from our customers over the phone."

SAP published an item about the fake phone calls in its customer magazine at the end of last month, he said, but did not issue a broader statement about the situation.

Berner said SAP knows little about the parties making the false service calls, and advised customers -- under no circumstances -- to render confidential information over the phone. He could not confirm if the calls had occurred only in Germany or whether police were involved in the matter.