Tom Hardy has written a touching tribute to his canine "best friend" Woody.

The Legend actor took in Woodstock, nicknamed Woody, when he found the canine roaming the streets in Atlanta, Georgia while he was filming Lawless in 2011, and his co-star Jessica Chastain's parents looked after the 11-week puppy until Tom was cleared to take him back to the U.K.

Since then, Woody shared some of the spotlight with his famous owner, including appearing at premieres, in TV show Peaky Blinders, and on a People for the Ethical Treatment (PETA) campaign with Tom, and was even ranked as the 73rd most influential animal by Time magazine in 2016.

The usually private actor, who is married to actress Charlotte Riley, took to Tumblr this week (beg05Jun17) to announce "with great sadness" and "a heavy heart" that the Labrador-cross had passed away at age of six after a "very hard and short six month battle" with aggressive form of Polymyositis, or chronic muscle inflammation.

In his emotional tribute to Woody, he wrote, "He was an Angel. And he was my best friend. We went through so much together... Charlotte worked tirelessly with him to get him through a rough case of separation anxiety. He loved her like his Mom. And when she was pregnant he gaurded (sic) her fiercely."

The actor noted he doesn't usually write about his personal life but felt like he should because Woody was quite well-known.

"To the bestest friend ever. To me and to a family who loved him beyond words and whom he loved without doubt more than I have ever known (sic)," he continued. "Woody was the bestest of journey companions we ever could dream of having. Our souls intertwined forever.

"Thank you Woody for choosing to find us. We will love you and be with you and you with us forever. Never ever ever forgotten. Your Boy tom... With all of me I love you. Always Thankyou for Your love beautiful boy (sic)."

Tom's representative confirmed Woody's death to BuzzFeed and that the post, which was accompanied by a slideshow of pictures, was written by the actor.