Alice Evans has alleged she's "scared" of her estranged husband Ioan Gruffudd in an emotional post defending her right to speak out about her tumultuous marital split.

The 102 Dalmatians actress posted an emotional message on Instagram after claiming hours earlier to have been blindsided by her husband filing for divorce in Los Angeles on Monday.

"I can't sleep. Not a wink. I am terrified for what tomorrow will bring," Alice wrote on Wednesday. "I'm scared that my little girls will be disappointed by their Dads behavior and model that in their future relations with the opposite sex.

"I'm also scared of my ex-husband's response to the fact that I had commented on his sudden decision to serve me. I know he'll be angry. ( he is always angry - he was born angry)."

And she questioned the fact that many people told her to accept the split "with dignity".

"What is dignity?" she asked. "I think 'dignity' is a way of covering up our own hurt. I think dignity is a way of others telling us to shut up, because THEY don't want to think about our hurt."

After running out of space, she continued to defend her right to be transparent on a subsequent post in which she alleged Ioan still has control of her Twitter password.

Alice also gave her own account about how their children - Ella, 11, and Elsie, seven - reacted when she told them about the divorce.

She wrote: "My 7 yo got home from her dads and kindly, almost jokingly, but with intent showed her the article where it said that her daddy had filed for a divorce form her Mommy in the High Court of Los Angeles and he hadn't told us so he probably hadn't told her either so we were just letting her know and she ran away screaming saying 'no!! No! My daddy would NEVER do that to my Mommy'.

"(At this pinpoint I imagine some mothers who DONT believe in telling their kids the truth about everything will object. That's fine. My ex-husband believes in lying rather than harsh truths."

According to editors at The Sun, documents obtained by the publication show Ioan filed to formally end their 13-year marriage at the Los Angeles Superior Court.