Claiming fresh threat to his life, Joshi, a known detractor of Gujarat Chief Minister Narendra Modi, has written to Union Home Minister P Chidambaram seeking more security.
He claimed he had received fresh threat calls on his mobile phone from three different numbers and also through letters.
In a statement issued here, Bhatt made an appeal to Joshi "to visit Gujarat and expose those elements giving him threats".
Bhatt alleged "fake CDs" about Sanjay Joshi were sent to Mumbai from Gujarat during the national executive committee meeting of BJP, following which, Joshi had resigned from the post of BJP general secretary.
"Why did the BJP central leadership keep quiet on finding out who was responsible for the distribution of this fake CD"? he said.
Bhatt alleged the BJP leadership was under the "influence" of Narendra Modi, "which is why it has not taken any action".
The BJP government has "failed" to arrest those responsible for the murder of former Gujarat Home minister Haren Pandya nine years ago, he said.
