Actress Alice Evans has accused her estranged husband Ioan Gruffudd of having a three-year affair before they split up.

Alice made the claims on Twitter after her 48-year-old ex posted Instagram snaps of himself with his new girlfriend Bianca Wallace for the first time on Wednesday.

Slamming Ioan on social media, Alice, 50, wrote, "So it turns out that my husband, after two years of telling me I'm a bad person and I'm not exciting and he no longer want so to have sex with me and he just wants to be on set abroad... Has been in a relationship for THREE years behind all our backs. Good luck, Bianca."

The actress, who married Ioan in 2007 after meeting on the set of the 2000 movie 102 Dalmatians, claimed she learned of her estranged husband's relationship with Bianca after his new love shared the same image on Instagram that he had sent to their eight-year-old daughter.

"I have no words," she tweeted alongside the picture of people sitting on a beach on a cloudy day. "My husband sent this to Elsie, our 8 yo last week and asked her if she thought he was a good photographer. I am lost. Totally lost and sad and confused..."

Back in January, when announcing the split, Alice tweeted, "My beloved husband/soulmate of 20 years, Ioan Gruffudd, has announced he is to leave his family, starting next week. Me and our young daughters girls are very confused and sad. We haven't been given a reason except that he 'no longer loves me (sic).'"

Ioan filed for divorce in March, a move that also allegedly blindsided his ex, as she wrote on Instagram the filing came "out of the blue". She has also accused him of "gaslighting" and "mentally torturing" her.

In addition to Elsie, the couple also shares another daughter, Ella, 12.