I got a phone call this morning purporting to be from Hammersmith police station, saying that £2000 had been spent from my account in Selfridges this morning. Being old & (l like to think) wise, I asked for his name and number and said I'd ring him back, & he gave me those & told me to ring him on 161. When I did this the same voice answered so I hung up. I then called the police & they said they had many similar calls & it was a scam. Just to be sure, I called my bank who confirmed this that with a sum like that, they would contact me for confirmation. The police also said,regarding the 161 number,that it doesn't exist,& the scammers don't hang up,thus leaving the line open so that you get straight back to them.
Hope this is helpful