What does the copper want with Phelan in Coronation Street?

What's Phelan hiding from Eileen and Nicola and what does the policeman who comes to visit want?

Crooked builder Pat Phelan has good reason to be fearful of the police, and events take a nasty turn for him when daughter Nicola brings a policeman straight to his door in Coronation Street.

In this case, the policeman in question isn’t visiting Phelan on official business, but it’s still a difficult situation and one he’d rather avoid.

Phelan’s wife Eileen has noticed he’s been behaving oddly. What’s he hiding from her, and will the policeman get too close for comfort?