Brazilian campaigners Thursday handed in a one million names-strong petition asking asylum for US intelligence whistleblower Edward Snowden.

In a comic take on efforts to give the former National Security Agency employee a refuge, a man clad in a giant papier mache head bearing Snowden's likeness tried to grasp a giant passport held by another campaigner purporting to be Brazilian President Dilma Rousseff.

Holding Rousseff back was a third campaigner wearing a papier mache mock-up of US President Barack Obama.

Global campaigning organization Avaaz launched the petition in December and has since obtained 1.1 million online signatures from around the globe demanding Rousseff offer Snowden, currently in Russia, refuge.

"The Brazilian government had said it required a formal request from Snowden to grant asylum. Today, more than a million people have done what Snowden cannot and presented this request in his name," said Avaaz director Ricken Patel in a statement.

"We are handing in the document to the foreign ministry," Avaaz campaigns director Michael Freitas Mohallem told AFP.

Snowden wrote an open letter to Brazil published in December praising the country as one of the world's "most interesting and vibrant democracies."

In the letter, Snowden said he was ready to help the Brazilian Senate's investigation of US eavesdropping, which targeted the communications of President Dilma Rousseff and Petrobras, the state oil giant.

But he added he was not offering to swap information for asylum.

The NSA snooping infuriated Rousseff, who canceled a state visit to Washington scheduled for October in protest, and pushed for a UN resolution aimed at protecting "online" human rights.

But she has not commented on a possible asylum request as Brazil says it has not received one.

The foreign ministry confirmed that remained the case and a spokesman said Thursday's petition would be handed over to the justice ministry.

Earlier this month, a Communist Brazilian senator nominated Snowden for this year's Nobel Peace Prize, judging his leaks had contributed to world peace.