Google has been accused of taking more Java code to use in its Android mobile operating system.
Open source advocate and software patent blogger Florian Mueller claimed he had found as many as 37 files marked "Proprietary/Confidential" in Android which had been taken from Oracle's Java code.
Alongside the initial seven alleged instances of copyright infringement, Mueller said he had discovered six more files in another directory which showed the "same pattern of direct copying."
"All of them were apparently derived with the help of a decompiler tool," Mueller said in a blog.
"Those files form part of Froyo (Android version 2.2) as well as Gingerbread (version 2.3), unlike the file presented by Oracle."
Last year, a lawsuit between Google and Oracle kicked off, with the latter handing papers over to a federal court, suggesting Java code was pilfered by the search giant.
Google claimed Oracle had redacted or deleted important material when Larry Ellison's firm produced a comparison between the Android code and Java.
Mueller claimed six of the files had been relicensed under the Apache license without permission.
In a follow-up blog post, Mueller has also suggested the Oracle code he had discovered could also be found in "open source code distributions of different Android device makers, including at least Motorola, LG, and Samsung."
"I'm sure those companies didn't intend to infringe Oracle's rights. They probably relied on the presumed legality of the Android codebase," he said, admitting he had not been able to check whether the relevant code was also shipped with the devices themselves.
Other vendors, including HTC and Dell, have removed the related files from their own source code.
Google chose not to comment on the situation.
From the man himself
IT PRO caught up with Mueller this morning, who said he had not been contacted by Oracle about the findings yet.
Mueller had previously voiced his opposition to Oracle's acquisition of Sun, Java's original developer.
"What I want is what a lot of people want just to try to figure out from the outside what is going on inside that black box... that this legal case is [based around]," Mueller said.
"My impression when I saw Google's response to Oracle was that [they threw] in the kitchen sink, in terms of raising lots of defences."
He suggested Google has tried to "clutch at every straw they have" in order to prove Oracle wrong.
