When contacted for a reaction, Singh said he has nothing to say as former Law Minister H R Bhardwaj has already clarified the issue.
Bharadwaj earlier insisted that no "undue favours" were given to the judge because proper procedure was followed.
"So far as political threats to a coalition government is concerned there were always pressure(from allies) on appointment of judges which I never yielded," he said.
Meanwhile, close aides of the former Prime Minister asserted that nobody approached Singh at airport at any time during departure or arrival from a foreign visit as stated by Katju.
They said that there was, in fact, no scope for such a meeting at the airport as the then Prime Minister would get down from his car just next to the aircraft Air India One before boarding it.
Bhardwaj said records will prove that during his tenure as Law Minister in UPA I, the judiciary was fully insulated and whatever appointments were made have been outstanding.
Rejecting that government was pressurised on the issue, he said "there is no question of pressurising me. Yes, 18 MPs came including their Minister of State.
"They said injustice is being done to this person who was from the Scheduled Caste and our people are very angry with it. I said I cannot decide it, it will be decided by the Chief Justice of India."
He said the MPs wanted the additional judge to be elevated as a permanent judge. "Their views were sent to the CJI and he decided not to confirm him (as permanent judge) straightaway. He said he will hold a discreet inquiry and after that it will be decided," he said.