Hostilities between two of the most prominent tech giants, viz. Microsoft and Google, extended further after the Redmond-based software giant accused the Web search firm of misleading the US Government and the general public about the security certification of the its Internet-based suite of office tools- "Google Apps for Government."

Google says that "Google Apps for Government" had not been certified under the Federal Information Security Management Act (FISMA). The certification signifies that the certified product meets the government’s standards.

But, Microsoft says court documents shows that Google’s concerned product has so far not been certified under the FISMA, and is still being reviewed.

The unleashed documents are part of a Google lawsuit claiming that it was inappropriately thrown out of competing for a U. S. Department of Interior contract to build a new e-mail system for around 85,000 employees. The contract was won by Microsoft. But, a judge believed that the bidding was rigged to help Microsoft, and issued an injunction.

In response to Microsoft's accusations, Google claims that a version of Google Apps has already gained FISMA clearance.

The Web search giant said, "We did not mislead the court or our customers. Google Apps received a FISMA security authorization from the General Services Administration in July 2010.”

Relations between the two tech giants have been becoming more and more acrimonious. Previous month, Microsoft in Europe joined an anti-trust complaint against Google over Internet search.