"I have still not decided about joining politics," Dutt, who is in Kashmir shooting for Rahul Dholakia's "Lamhaa", told TV channels.
However, Amar Singh denied having announced Dutt as a party candidate for the Lok Sabha elections from Lucknow without consulting the actor.
Amar Singh said: "I have not heard his statement. I did not announce his candidature without consulting him."
"His candidature from the Lucknow parliamentary seat is decided. Matters will be clear to everyone Jan 17, when Sanjay Dutt is to arrive in Lucknow. He wants to do good work in public life," he added.
Amar Singh had announced the actor's candidature for the Lucknow constituency Jan 8.
On Wednesday, the actor's politician sister, Priya Dutt, had said that neither Dutt nor (his wife) Manyata had confirmed that he is contesting the election.
She also claimed she had been kept in the dark about his decision to join politics. "Just like their marriage, I came to know about it through the media. We haven't had any discussion on this in the family but there is no family feud. If the need arises, we as a family will support Sanjay," she had said.
Asked if Priya's comments have hurt Sanjay Dutt, the Samajwadi Party leader said: "I have not spoken to him on this issue. He has not told me anything. He is very sensitive."
"Yeh khoon ke rishte hain, ghar ki baat ghar mein rehne dijiye. (These are ties of blood, let the family talk remain within the family)," Amar Singh added.