EXCLUSIVE: A beloved actor is poised to play a belovedHarry Pottercharacter.

HBO declined to comment.

As we make our way through pre-production, we will only confirm details as we finalize deals.

John Lithgow and Michael Gambon as Dumbledore

John Lithgow and Michael Gambon as DumbledoreJessica Howes / Murray Close/ Warner Bros./ Courtesy Everett Collection

Jude Law played a younger version of the character in theFantastic Beastsprequel films.

While all of them are British or Irish and Lithgow is American, he has played British characters.

The rumor mill had been going into overdrive for monthswith speculation on who would playthe books most iconic characters.

‘Harry Potter’ TV series

Lithgow, a two-time Oscar nominee, co-stars in current Oscar contenderConclave.

He also is attached to narrate a potential Trinity Killer prequel series,now in the works.

The production will soon transfer to the Harold Pinter theatre in the West End.

Lithgow is currently narrating New York City BalletsCarnival of the Animals.

He wrote the narration in 2003, drawing on his illustrated childrens book of the same name.

Lithgow is repped by UTA, Anonymous Content, Hansen Jacobson Teller and Viewpoint.