The actor starred alongside the former Glee star on Broadway.
The actor elaborated on previous claims she made about Lea's behind-the-scenes behaviour.
The actor also said she was proud of Glee co-star Samantha Marie Ware for “standing up for herself” and “not being fearful.”
Lea Michele Apologises After Glee Co-Star Samantha Ware Said She Made Working On Show 'A Living Hell'
In an Instagram statement, Lea said she apologises for "my behaviour and for any pain which I have caused".
Samantha Ware recently claimed that Lea made being on the set of the show a "living hell" for her.
The two actors worked together on the musical TV series in 2015.
He was found dead earlier this week, at the age of 35.
'Having compassion for Mark Salling in no way minimises his crimes.'
Husband Ryan Dorsey says she struck him on the lip and head.
The 35-year-old actor could face four to seven years in prison.