Airport sources said Karti arrived by a British Airways flight around 4 am.
He had left for London on May 18 on what his father described as a scheduled trip.
"Karti is travelling as per earlier travel plans. He will return after a few days. There is no ban on his travel," his father and senior Congress leader P Chidambaram had said.
The CBI on May 16 had carried out searches at Karti's homes and offices in four cities to probe charges that he had received money from a media firm owned by Indrani and Peter Mukerjea to help them evade a tax probe.
The CBI had filed an FIR against Karti and the Mukerjeas on charges of criminal conspiracy, cheating, receiving illegal gratification, influencing public servants and criminal misconduct.
It alleged that Karti received money from INX Media for using his influence to manipulate a tax probe against it in a case of violation of Foreign Investment Promotion Board conditions for an investment from Mauritius.