India said Wednesday criminal cases were lodged against four non-profit groups accused of fuelling protests against planned atomic power stations because they "diverted" overseas donations.
Home Minister P. Chidambaram would not name the non-government organisations (NGOs) targeted in the police cases.
But "on an inspection of accounts and other information available to the government, there are reasons to be believe that the funds (the NGOs received) have been diverted," he told reporters.
India has previously said the NGOs were drawing funds from the United States and Scandinavian countries and using them for anti-nuclear protests.
"They were not used for the purposes for which the foreign funds were received. But to whom they (the funds) were diverted — how they were diverted — will come out in the investigation," Chidambaram said.
Assets of the NGOs had been frozen and they were being booked for violating the provisions of India's Foreign Contribution Regulation Act, he said.
India's plans to build a nuclear power plant in the southern state of Tamil Nadu and another in the western state of Maharashtra have been thrown into disarray following the protests by villagers and activists.
NGOs operating in the area have denied the government's allegations.
Chidambaram said experts have certified the safety of the nuclear plants.
"My position is that India faces a huge power shortage and unless we tap every source of power we will not be able to sustain a high growth rate, Chidambaram said.
In an interview published last week, Prime Minister Manmohan Singh blamed US non-profit groups for whipping up the anti-nuclear row that has stalled the two new plants.
India's economy is dependent on coal, but Delhi hopes to raise the proportion of power produced from nuclear sources from less than three percent to 25 percent by 2050.