CORONATION Street’s big mystery about Tia Wardley has deepened tonight with an explosive twist.

For months the name has been hanging over Carla Connor and girlfriend Lisa Swain in connection to Lisa’s dead wife Becky.

And tonight Tia finally arrived on the cobbles to explain herself – just in time for the women’s engagement party.

In today’s episode DI Costello was seen desperately trying to cover his tracks and hiding what he really knows about the mysterious Tia Wardley.

Tia turned up at the Bistro and told Lisa and Carla all about her connection to Becky.

She claimed to have been involved with the Radcliffe brothers and revealed that Becky had helped her escape her troubled life out of the goodness of her heart.

Lisa seemed genuinely touched that the truth meant that Becky had been a good cop – and had helped the woman escape a bad situation.

But after leaving the Bistro, the woman met up with Costello – and the truth soon emerged.

The woman was not the real Tia Wardley.

“I gave them the full Meryl Streep,” she told Costello.

“Really milked it. Looked like the blonde one was going to cry.”

And when the potentially dodgy cop questioned whether she actually managed to trick Lisa, the faker added: “They didn’t have a clue what the real Tia Wardley looked like, so yes…”

In addition to the on-screen confession, the credits also named her as “Fake Tia Wardley” confirming that she is definitely not the real woman Lisa and Carla were looking for.

But as Lisa and Carla made their way home from the celebrations, Lisa suddenly felt a chill.

It was then revealed that someone had been watching the couple, leaving the detective feeling completely unnerved.