While talking to mediapersons in Patna, the JD(U) leader said it was for centre to explain whether it was proper for people occupying constitutional posts to indulge in spying.

The Congress party pulled down the Chandrashekhar government in 1991 after a Haryana police constable was allegedly caught spying outside the residence of former prime minister Rajiv Gandhi in New Delhi.

"If Congress has some moral, it should explain whether such conduct is appropriate. If not, it should immediately sack the Governor," he said.

At a press conference, Singh defended his recommendation for dissolution of the Bihar assembly saying none could question his authority and reports.

"Nobody can question my authority and contents of the reports which I had sent to the Centre on the political developments in Bihar as these were based on facts and were in accordance with constitutional propriety," Singh said. When asked if he also meant the judiciary, he said 'nobody means nobody'.

Singh also dubbed as 'baseless' the BJP's statement describing as 'an exercise in presumption', his report on May 21, which led to the dissolution of the state assembly on May 23 and its allegation that Singh had acted at the behest of RJD chief Lalu Prasad.

"I reiterate that my reports were based on facts," he added. He refused to take questions on whether he had submitted any evidence in support of his statement about 'horsetrading' by the NDA to form a government and 'restiveness' among RJD MLAs.