In the thick of a controversy, Union minister Praful Patel on Tuesday urged Civil Aviation minister Ajit Singh for a thorough probe into the change of aircraft by Air India allegedly to accommodate his family members on a trip to Maldives in 2010.

In a letter to Singh, Patel referred to news reports appearing on Tuesday and some on earlier occasions relating to an RTI query wherein it has been alleged that some members of his family travelled from Bangalore to Male and back in an Air India Flight which had been changed to a larger aircraft so as to enable them to travel by business class.

"I am personally embarrassed and pained about the impression that is sought to be created that (a) the passengers travelled either on free tickets or were upgraded to business class, whereas they were actually fully paid business class passengers; (b) it was done at my behest; "(c) Air India or any private Airlines has never done change of aircraft type ever before if they have more bookings or for commercial reasons," he said in his letter.

Therefore, Patel requested Singh to "immediately order an enquiry and ascertain all the facts or probe the matter in any way you deem appropriate."

"I would be very obliged if you take this up at the earliest so as to clear the doubts and wrong impression which have emanated out of the RTI query and sensationalised media reports," he said.

Asked about this controversy, Singh told reporters, "they (Air India) should not have done this (changing the aircraft)."