Months ahead of the Delhi elections, the Congress party appears to be mired in a tussle over a "personal letter" sent by former chief minister Sheila Dikshit's son Sandeep Dikshit to the state unit in-charge PC Chacko.

Dikshit declined to divulge the details of the letter, though the issue has been referred to the party's disciplinary committee, comprising senior leaders AK Antony, Sushil Kumar Shinde and Motilal Vora, according to senior leaders who asked not to be named.

"The letter was for Mr Chacko and for no one else. It is not a legal notice, but a personal letter," Sandeep Dikshit said on Friday.

Sheila Dikshit, a three-term Delhi chief minister, died of illness on July 20.

Chacko, too, did not reveal the contents of letter, but said he had sent it to the Congress's top leadership. "I have sent a copy of the letter to Mrs Sonia Gandhi. Nothing is personal between me and Sandeep Dikshit, everything is official," he told HT.

"If the Congress party has to revive, Mr Chacko should be removed," the Delhi Congress spokesperson Jitender Kochar said.