(Cover) - EN Showbiz - Kiefer Sutherland says watching back episodes of 24 gave him a bit of an eye-opener.

The 43-year-old actor is well known for his portrayal of Jack Bauer on hit US drama series 24 which follows the adventures of a counter terrorist agent.

Kiefer first began work on the show at the turn of the decade, with the recent eighth season the last and a 24 movie in the pipeline.

Kiefer is feeling particularly nostalgic about the end of the show, and admits watching it back makes him realise how much hes changed over the past ten years.

Our ageing is documented through the show its a bit of an eye-opener. Though if you actually do the math, Jack Bauer is now about 85 years old! he laughed in an interview with Empire.

Kiefer is helping make a documentary focusing on the programme, and he thoroughly enjoyed looking back at past episodes. The task did reveal how much the stars sense of humour has altered lately though.

Were putting a documentary together, so I sat down with Rodney Charters, the cinematographer, to look at behind-the-scenes footage from the last eight years. We were laughing, then it got to stuff from the later seasons and it wasnt funny anymore, he added. (C) Cover Media