Web giant Google has rebuffed a claim by systems giant Oracle that it would owe between $1.5 billion and $6.1 billion if found guilty of infringing patents relating to the Java programming language.

Google said in a statement that the estimate, made in a court filing from Oracle last week, is "based on fundamental legal errors".

Oracle sued Google last year, claiming that the company’s Android mobile operating system infringes on Java patents that Oracle owns as result of its acquisition of Sun Microsystems.  

If the upper band of Oracle’s damages estimates were to prove accurate and Google was found guilty, the case would almost pay for the $7.4 billion Sun acquisition on its own. And if Google were forced to pay royalties on Android, it may have to start charging manufacturers to use it, possibly damaging its popularity.

Last week, Oracle became the target of its own high-profile legal dispute, as former partner Hewlett-Packard sued over its decision to discontinue support for Intel’s Itanium chips, on which certain HP servers are based.