Image caption More and more smartphones are using the Android operating system

Business software maker Oracle has filed a lawsuit against Google, accusing the search engine giant of infringing patents on its technology.

Oracle says Google infringed patents on its Java software while developing its Android operating system.

Oracle acquired the Java technology when it took over Sun Microsystems in a deal agreed last year.

Android is fast becoming one of the most widely used operating systems used in smart mobile phones.

Google "knowingly, directly and repeatedly infringed Oracle's Java-related intellectual property," Oracle said.

"This lawsuit seeks appropriate remedies".

The lawsuit was filed on Thursday night in the US.