ANKARA (AFP) - Turkish Prime Minister Recep Tayyip Erdogan on Friday criticised a Constitutional Court ruling that lifted his government's March 20 ban on Twitter.

"We are of course bound by the Constitutional Court verdict, but I don't have to respect it," said the premier, a day after the US-based social media site went live again in Turkey.

"I don't respect this ruling."

Mr Erdogan's government has been rattled by the twin crises of street protests since last June and, since December, a torrent of online leaks on Twitter, Facebook and YouTube which appeared to implicate the premier's inner circle in corruption.

YouTube remains banned since it was also used to leak an audio recording that was purportedly of a conversation of top government, military and spy officials weighing possible military action inside neighbouring war-torn Syria.

Mr Erdogan said on the Twitter case, that "the Constitutional Court should have rejected" the application to lift the block on the site which had been brought by an opposition lawmaker and two academics.

"All our national, moral values have been put aside," he said about the spate of anonymously posted recordings.

"Insults to a country's prime minister and ministers are all around."

The Internet crackdown has sparked protests from Turkey's Nato allies and human rights groups, who have deplored it as curbing the right to free speech - a notion Mr Erdogan dismissed.

"This is a commercial company which has a product," he said of the San Francisco-based micro-blogging service.

"It is not only Twitter. YouTube and Facebook are also commercial companies. It is everyone's free will whether or not to buy their product. This has nothing to do with freedoms."