‘Found it, officers . . . Julie Lane dealt with the sale but she’s on maternity leave just now.’

Petty held up the file, then invited them to take a seat at his desk.

‘Do you mind taking notes?’ Jane asked Teflon, who got his pocket notebook and pen out of his coat.

Petty opened the file and took out the paperwork, then flicked through it before removing a page.

‘Here we go – the previous owner of flat forty was a Mrs Elizabeth Smith. It says here she died of cancer and her son, whom I assume inherited her estate, sold the premises to the Clarkes for just under fifteen thousand pounds.’

‘Do you have the son’s details?’ Teflon asked.

‘Mr Graham Smith, flat forty Edgar House.’

‘Is there any other address shown for him?’ Jane asked.

‘No, looks like he lived with his mother. There’s a contact phone number if that’s of any use.’

‘Yes please,’ Teflon said.

‘01-808-3503 . . . Wanstead’s on the 989 exchange, so that’s not a local number.’

‘Do you have any previous history of the premises prior to Mrs Smith buying it?’ Jane asked.

‘Only that it was owned by the local housing association when Mrs Smith lived in it, and then she bought it from them. I know the manager of the association, so I can make a quick call and ask him to check his files.’

‘Thank you, Mr Petty, that would be very helpful,’ Jane said.

Jane spoke quietly to Teflon as Petty called the association manager.

‘The neighbour on one side of flat forty said Mrs Smith lived alone and a man in his mid-to late forties sometimes visited her. I didn’t think anything of it at the time, but with what we know now it would be worth revisiting her to get a description of him.’

Teflon agreed and suggested they go to nearby Edgar House when they’d finished speaking to Mr Petty.

Petty put the phone down and looked at the notes he’d made of the conversation.

‘Mrs Smith had lived in the flat for a number of years and the association knew Mrs Thatcher was going to introduce the government’s “right to buy” scheme. They decided to test the waters and offered some long-standing residents the opportunity to buy their flats at a reasonable price – Mrs Smith being one of them. Her son paid just over ten and a half thousand pounds for it.’

Teflon whistled. ‘That was a nice quick profit.’

‘How did he pay?’ Jane asked, wondering if they could locate him through a bank account.

‘Cash.’

‘All of it?’ Jane and Teflon asked in unison.

‘Yes.’

‘How did Mrs Clarke pay him?’

‘I don’t know, the final exchange was dealt with by solicitors and they won’t divulge that sort of information.’

‘One last thing, Mr Petty . . . Do you know how many keys were given to Mrs Clarke for the flat?’