Khan made the remarks in an interview with a private tv channel. The PTI chairman said Gill had been beaten after being stripped.
Khan alleged that Gill was being coerced into implicating Khan in connection with his recent anti-military tirade.
The PTI chief went on to allege that Gill was also asked to "reveal" how many times General Faiz had called on Khan. The one-time prime minister's dietary preferences were also 'probed' into, he said.