Josh Brolin has apologised for breaking California's strict stay at home orders to visit his dad James Brolin and stepmother Barbra Streisand.

The 'Avengers: Endgame' star received criticism online last week when he and his wife Kathryn Boyd took their daughter Westlyn Reign to visit her grandparents, despite the social distancing and self-isolation rules that have been put in place amid the coronavirus pandemic.

And in an Instagram video, the 52-year-old actor has now admitted his actions were ''irresponsible''.

He said in the clip: ''My father lives next door to us and we had a plan to go see them and not be near them and that plan was broken and that is our responsibility. We were going to pick something up and show Bean the pool and and I think it was irresponsible.

''It's hard to be honest sometimes, it's hard to be honest and say, 'Well maybe I screwed up.' The responses brought me back to my own truth. It's humbling as hell, because I know there are some people out there with no masks, no gloves, no interest in it, they think it's in your head, that you'll survive because of immunity that is created because of your own psychic weight. But I know for me that's not the case and we've been very responsible and I apologise about that.''

Josh then insisted he is ''not an advocate'' for breaking quarantine rules ''outside of taking care of each other''.

He added: ''My apologies, and I'm not an advocate of doing anything outside of taking care of each other and making sure we get through this even if we go overboard and are too protective. We'll look back on this as being a short time for a very long term solution and a long life.''

The actor and his family came under fire after Barbra, 77, shared a photo of Josh's wife Kathryn wearing a protective mask whilst holding up a sign that read: ''We (heart) you Gamma & Grampa (sic)''

She captioned the image: ''I just love the sign that Josh and Kathryn painted yesterday when they came to see us with our little grandchild Westlyn!

''P.S. all of the flowers are now blooming on our wishing well -- we are wishing with our hearts and minds for everybody to stay well! (sic)''