"My conscience is clear, I have done no wrong, I am being hounded by Prem Kumar Dhumal, his sons and the BJP at large," Singh told media.
The Himachal Pradesh CM said he has the support of Congress supremo Sonia Gandhi.
"I have blessings of the Congress high command and above all blessings of the people of Himachal Pradesh," Singh said.
Meanwhile, the Income Tax (I-T) department has started investigation into the alleged irregularities in Singh's agricultural income, said reports on Saturday.
"IT authorities have allegedly stumbled upon revelations that tonnes of apples from Virbhadra Singh's orchards were transported in oil tankers and on two wheelers," reported CNN-IBN.
"The IT authorities are investigating Virbhadra Singh's agriculture income after he claimed that the revenue amounting to Rs 6.56 crore was generated through the sale of apple orchards in the last three years," said the news channel.
Virbhadra Singh said a Life Insurance Corporation of India (LIC) agent Anand Chouhan, who manages his orchards, sold the apples on his behalf and got the money.
Earlier, levelling corruption charges against Virbhadra Singh over payments from a power company's promoter, senior BJP leader Arun Jaitley on Dec 30 said he has written a letter to Prime Minister Manmohan Singh demanding action.
Jaitley said he has written to Singh and the director of the Central Bureau of Investigation (CBI) on the matter, enclosing copies of all relevant documents, which he considers "an open and shut case" against the Himachal Pradesh CM.
"I have written a letter to Manmohan Singh with copies of all relevant documents and have sent to the CBI director also," Jaitley said while addressing a press conference here.
"Among all corruption charges, I have seen in the past few year, this has been the most open and shut case against the present Chief Minister of Himachal Pradesh Shri Virbhadra Singh...in which it may be not difficult but almost impossible to take a second view," he said demanding probe.
Virbhadra Singh alleged that Venture Energy and Technology Pvt Ltd had defaulted on a contract concerning hydropower project work inHimachal Pradesh, but was given an extension in the time to complete the job.
He said that Virbhadra Singh had given the company 10 months more, and alleged that the firm's promoter had made cheque payments of Rs.3.5 crore "to Virbhadra Singh and his wife Pratibha Singh".
Virbhadra Singh and his family became shareholders in another firm belonging to the promoter of the power company, he said.
Pratibha Singh is a member of the Lok Sabha.
--IBNS (Posted on 04-01-2014)