Mark, who played Noah 'Puck' Puckerman in the hit musical TV show, is said to have been taken into custody yesterday amid allegations that he was in possession of child pornography.
The reports were first made by US TV show Crime Watch Daily, who have since stated he has been released on a $20,000 bail while LAPD officers continue with their investigations. Mark has not been charged in connection with any offences.
Lt. Andrea Grossman, from Los Angeles Police Department, has since confirmed the arrest to the New York Daily News, adding: "I would imagine that would surprise anybody." She also said police forced their way into Mark's California home at 7am local time yesterday (29 December).
A rep for American actor Mark is yet to comment. The star last tweeted from his Twitter account on Christmas Day, where he shared a picture of himself with fans while holding a squirrel.
Mark, 33, shot to fame in 2009 thanks to the Fox series Glee. Mark was among the original cast, including Lea Michele and the late Cory Monteith, who played his on-screen best friend Finn.
Corey passed away following a drugs overdose in a Canadian hotel room in 2013.
Mark continued to star in Glee with a reoccurring role until the show finished earlier this year. During his time on Glee, he was nominated for many awards including both Screen Actors Guild and Teen Choice awards.