The actress, best known for playing memorable Weatherfield villain 'Mad' Maya Sharma, is to appear as new consultant Alex Broadhurst - who arrives at the hospital next month as part of a storyline for established character Michael Spence (Hari Dhillon).
Holby City's new producer Justin Young teased the upcoming arrival of Alex in an interview with Inside Soap.
Young commented: "She's smart, dry and professional. Hanssen brings her in to steady the ship and assess whether Michael is capable of taking over his old job after the plastics scandal.
"Michael has no idea how to handle Alex, and she's immune to his charms. She's a rival to Michael, and it's all about whether he can figure her out."
Young also revealed that former EastEnders star Hannah Waterman and ex-Emmerdale actor Luke Tittensor will soon be making guest appearances on Holby.
"Hannah… plays a very sassy patient who has a lovely episode with Michael," he said. "Luke Tittensor is also coming into Holby as Eddi's younger brother Liam. He'll be arriving next month, so that's very exciting. Luc takes Liam under his wing and that unsettles her."
Holby City airs on Tuesday nights at 8pm on BBC One.
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