Carver, who was ahead of me, spoke without turning.

‘This is the hub of Mr Slack’s business empire,’ he said. ‘From here he oversees the running of his restaurants, pubs, clubs and property portfolio.’

‘So what about all the other stuff he’s involved in?’ I asked.

He stopped walking and turned to face me, a frown gathering on his brow.

‘You’ve lost me,’ he said. ‘What other stuff are you talking about?’

Jesus, I thought. This creep knows how to play it cool.

‘I’m talking about the businesses that bring in the real money – like the drugs and prostitution and smuggling and so forth.’

His lips stretched into another mirthless grin.

‘Nice try, my love. But you lot really need to accept that you’ve been barking up the wrong tree for years. My boss is a legitimate businessman. He’s not a gangster. If he was I’m sure that even half-wits like you would have been able to prove it by now.’

Our eyes locked briefly and I could see he wanted me to respond. But when I didn’t he shrugged his shoulders and carried on up the stairs.

I stared at his back and told myself that when Roy Slack was eventually taken down I’d do all I could to make sure that this cocky bastard was right there alongside him.

On the top floor there was a carpeted corridor with two open doors on either side.

We followed Carver past a small kitchen and then a room containing a long conference table.

The walls were painted a soft grey and there were a few hanging prints of old London.

There was no sign of life until we got to the last room on the right. Slack’s office. He was sitting behind a large mahogany desk wearing a white open-neck shirt that was too tight across his chest and stomach.

Carver stood to one side and waved me into the room. Kate followed, but I gestured for the uniforms to wait outside in the corridor. Then I whipped out my ID and showed it to Slack.

‘DI Laura Jefferson,’ I said. ‘I’m here with DS Kate Chappell.’

‘And let me guess,’ he said. ‘You’re with the organised crime task force.’

I nodded. ‘We are.’

‘Well, you didn’t waste any time did you? Fresh from putting poor Harry Fuller away you’ve decided to get back to harassing me.’

‘We need to ask you a few questions, Mr Slack,’ I said. ‘And for your information we have a warrant to search this office and seize your phones and computers.’

His eyebrows knitted together.

‘This sounds serious,’ he said. ‘Should I call my lawyer?’

‘That’s up to you. But if you choose to we’ll have to conduct the interview at the Yard.’