Hours before Congress leader Virbhadra Singh is to be sworn in as the Himachal Pradesh chief minister for a record sixth time, he and his wife Pratibha Singh were acquitted in a corruption case on Monday.

The case pertained to the misuse of official position and criminal misconduct when Singh was the chief minister of Himachal Pradesh in 1989. He had to quit the Union cabinet after charges were framed against him in June.

The matter had hit the headlines in May 2007, when former state minister Vijai Singh Mankotia released an audio CD allegedly containing telephonic conversations of Singh and his wife with IAS officer Mohinder Lal and some industrialists, regarding monetary transactions for investment in the state.

Singh had maintained all along that the case was fabricated.

On Monday, while pronouncing the 24-page judgment, special judge BL Soni said, "There is no evidence relating to commission of any misconduct on the part of Virbhadra Singh and his wife Pratibha Singh; therefore, they are acquitted of the charges."

Singh, who returned from Delhi on Monday afternoon, was present in the court along with his wife.

(With agency inputs)