WASHINGTON - THE world's biggest Internet search company, Google, is accusing rival Microsoft's Bing of copying its results, a charge Microsoft denies.

'Some Bing results increasingly look like an incomplete, stale version of Google results - a cheap imitation,' said Amit Singhal, one of the company's search engineers, on Google's official blog.

The allegations were first reported by search news website, Search Engine Land.

Google had noted that in the summer of 2010 Bing did not return any results for a misspelled search for the surgical eye procedure 'tarsorrhaphy'.

'Later in the summer, Bing started returning our first result to their users without offering the spell correction,' Mr Singhal said. 'This was very strange.'

But Microsoft argued its search was different. 'What we saw in today's story was a spy-novelesque stunt to generate extreme outliers in tail query ranking,' said Bing corporate vice president Harry Shum in an official blog post.