The off-duty Air India Express pilot accused of assaulting a passenger at the Indira Gandhi International (IGI) Airport here has joined the investigation and is being questioned by the Delhi Police, an official said on Monday. Captain Virendra Sejwal appeared before the investigating officer and cooperated with the probe, police said, adding that his replies were being examined in light of the available evidence.

"If the investigating officer is not satisfied with his explanation, he may be arrested in the assault case," a police source said. A senior police officer said the investigation is being carried out strictly on merit and based on the evidence collected so far. "Whatever information can be shared without hampering the process and outcome of the investigation will be made public," a senior police officer said.