As per reports, Police has registered an FIR in Mumbai against a Canada-based Indian resident.
According to the complaint with the DGP, a Canada-based NRI Gagan Vidhu made a post on Februray 24 afternoon: "Time has come to kill Anna Hazare. I will be next Nathuram Godse soon."
Gagan Vidhu expanded his threat the following day, on February 25: "... I am not kidding. I am coming to India soon. I will arrange for gun and shoot this modern ghandi (Gandhi). I hate (Arvind) Kejriwal so much I can do anything to spoil him."
The post continued: "I have collected all the documents - My friend Neil in New Delhi is working on it. We will expose Kejriwal soon, then I have to play role of Nathuram Godse. I am not joking. I am very serious. I can do anything for my Bharat Mata."
Not taking the threats lightly, an aide Ashok O. Gautam has lodged a first information report (FIR) with Thane police and sought immediate action in the matter.
The death threat has come ahead of the 77-year-old Hazare's proposed 1,100-km-long three-month march (padyatra) from Gandhi Ashram in Wardha to Ramlila Maidan in New Delhi to protest the Land Acquisition Act.
The foot march will begin from Gandhi Ashram at Sewagram in Wardha, and will end at Ramlila Maidan in New Delhi, Hazare said in a statement on Tuesday.
The march, on the lines of Mahatma Gandhi's historic Dandi march, is anticipated to take around three months to cover the distance till Delhi.
The schedule of the march will be decided in a meeting at Sewagram on March 9, 2015, he said.
Hazare had last month staged a two-day protest at Jantar Mantar in Delhi during the budget session of Parliament, under the banner of Bhrashtachar Virodhi Jan Andolan Nyas.
Several farmers' groups had supported the stir.
Expressing his displeasure over the response given by Prime Minister Narendra Modi to his last month's protest, Hazare said , "Farmers' groups from various states staged protests on February 23 to 25 last month , after which the central government had to promise the farmers that if the land acquisition ordinance was doing injustice to farmers they were ready to change it."
"The Modi government has now brought in the new bill. A look at this draft bill tells us that there is no difference between the ordinance and the bill. The new bill was only a ploy to confuse us," he said.
The decision to launch 'padyatra' was taken after holding talks with peasant leaders and farmers' unions in order to put pressure on the government, Hazare said.
(With inputs from agencies)