New Delhi, May 15 -- Television veteran David Letterman made a dramatic return to The Late Show with Stephen Colbert this week, openly criticising CBS during an emotional appearance with host Stephen Colbert ahead of the programme's scheduled conclusion later this month.

The episode marked one of Letterman's final appearances at the Ed Sullivan Theater in New York, the same venue where he hosted 'The Late Show' from 1993 until his retirement in 2015. Colbert succeeded Letterman that year and has remained host for more than a decade.

Talking about how he was also fired one day, Letterman said, "I came very close to being teary about that. You know what happened backstage? I'm standing [there]. A guy comes over, and he says he's from CBS,...