Coronation Street viewers were left divided over some suspicious behaviour by DI Costello on the ITV soap, amid hints he could be corrupt after scenes with Kit Green
20:30, 18 Aug 2025Updated 20:32, 18 Aug 2025
Lisa Swain was left suspicious of DI Costello on Coronation Street on Monday, having initially believed her colleague Kit Green was the one hiding something. But DS Swain is not the only one sure something much bigger is going on, with fans divided over what Costello could be hiding.
In the latest episode, we saw Kit seemingly make a discovery before noting down a phone number and Costello’s name. So when Lisa figured this out she was confused and keen to get to the bottom of it, even dropping Kit in it when she asked her boss Costello all about it.
It comes amid fans believing Costello is a corrupt officer and that the mystery police files he’s refusing Kit and Lisa access to could expose him, and his possible link to Becky Swain’s death. Nothing has been confirmed, and while Costello recently warned Lisa away she doesn’t seem overly worried about him.
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Lisa Swain was left suspicious of DI Costello on Coronation Street
In fact it’s Kit she knows is up to something after he recently tried to access Becky’s files. It’s this week that he admits to his partner Sarah Platt that said files, from a case Becky was working on before her death years earlier, seem to be linked to a case he is on at the moment.
The fact he was digging left him getting scolded by Costello, and Lisa confronted him too. But what neither of them know is that Kit has continued to look into matters in secret, but Lisa may have blown his cover.
She asked Costello why Kit would have noted down his name and number, knowing it wasn’t the one she had for him. Costello seemed clueless, but you could also tell he was panicked by the idea that Kit was onto him.
Whatever it is he’s hiding wasn’t made clear, but fans said there was a moment where his “mask slipped” and it became clear what he was up to. With him warning Lisa to stay away from Kit, telling her he will drag her down with him, his anti-Kit campaign was evident.
Kit Green seems to be onto Costello(Image: ITV)
Fans were once again under the belief that Costello needs the pair to stop looking into the files, but to also stay apart from each other. That said, some fans have come up with a new theory linked to this, but it would suggest Costello isn’t the corrupt one after all.
Some viewers are speculating Costello is protecting someone else who is corrupt, or perhaps someone higher up is the one to be worried about, and he’s looking into matters but wants no one else involved. One fan said on social media: “I don’t think it’s Costello it’s too easy maybe he protected someone higher up.
Another fan questioned: “Possibly, could be a higher up trying to frame him? He definitely knows something though. Whether it’s actually him or not.” So is someone out to get Costello?
Or is he hiding something seriously dark, and could it lead to the truth about Becky’s death being revealed? The scenes did nothing to cool theories of Costello being linked to this for some fans, but we’ll all just have to wait and see!
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