The demise of the popular character, who was killed by his the members of Night's Watch at the end of the last season, had shocked fans of the series. There are several theories about his return even though HBO and the cast have rubbished it.
Harington has reportedly been on set in Northern Ireland but the actor told Time Out that it was just to complete his death scene.
"I filmed some scenes of me being dead - (jokily) it's some of my best work," he said, adding, "I don't have a clue. I know how long I'm a corpse for, but I can't tell you that!"
The season six of the hit show will air in India on Star World Premiere HD from April 26.