A coalition of human rights campaigners on Tuesday urged the US government to fund efforts led by the Falungong spiritual movement to circumvent Internet censorship in China and other nations.

Congress approved 30 million dollars in the 2010 budget to combat cyber censorship in China, Iran and elsewhere. But lawmakers have voiced concern that the funding since 2008 has been used ineffectively.

In a letter to Secretary of State Hillary Clinton, rights advocates -- most from China -- urged that money go to the Global Internet Freedom (GIF) Consortium, originally set up to evade China's Internet "firewall."

"By taking the right steps, the United States can make a historic contribution to its own security and to the advancement of democracy by rapidly tearing down the information firewalls of the world's closed societies," it said.

The letter was signed by exiled leaders of the 1989 democracy uprising in Tiananmen Square including Chai Ling, Wu'er Kaixi and Xiong Yan, along with figures behind the landmark Charter 08 petition for greater freedoms in China.

Other signatories included Rebiya Kadeer, the leader of exiles from China's Uighur minority, along with activists campaigning for greater openness in Cuba, Myanmar, North Korea and Syria.

GIF software was designed by the Falungong, which was banned by China in 1999 and branded an "evil cult" following a silent mass gathering in Beijing by its members.

But the technology was also put to use last year by Iranians who circumvented censorship to organize protests against clerical hardliners via Twitter and other websites.

The letter said that GIF servers, which nearly crashed after the Iranian elections, could be upgraded to allow 50 million unique users a day, up from 1.5 million now.

Five senators -- Democrats Robert Casey, Edward Kaufman and Arlen Specter, along with Republicans Sam Brownback and Jon Kyl -- wrote a letter to Clinton last month voicing concern that the grant money was going to waste.

They faulted the State Department for restricting grants to groups working inside a country, countering that "the most successful censorship circumvention tools are operated remotely."

Clinton, who testifies before Congress on Wednesday and Thursday, last month urged China to conduct a thorough probe into cyberattacks on Google and pressed technology firms to resist censorship.