John Partridge will return to his role as Christian Clarke on EastEnders during its 30th anniversary live week of episodes.
Making the comeback for his sister Jane Beale's (Laurie Brett) wedding to Ian Beale (Adam Woodyatt), it follows a brief appearance in which he came back for a single episode - Lucy Beale's (Hetti Bywater) funeral last year.
Speaking to Digital Spy, John confirmed: "I am honoured to be returning to 'EastEnders' at this most exciting time to celebrate 30 years, and more importantly to find out who killed Lucy."
Christian left Albert Square with his partner Syed Masood (Marc Elliott) back in 2012, and John admitted previously that he couldn't return full-time as he was busy caring for his mother.
With the killer of his on-screen niece being revealed during the live 30 year episodes, John feels it was only right for him to be involved.
Dominic Treadwell-Collins, executive producer for the BBC One soap explained: "How could Jane get married to Ian without her brother there?
"Johnny Partridge and Christian Clarke are loved by the audience and his 'EastEnders' family, and we are all thrilled to have him back for our anniversary. And we'll be putting Johnny's extensive theatre experience to good use, as he is plunged into EastEnders' live week."
Barbara Windsor and Jo Joyner will also be returning for the anniversary in their roles as Peggy Mitchell and Tanya Branning respectively.