On Sunday, July 1, at 7.30pm, a woman aged 60 was at home in Keppel Road, East Ham, when she heard a knock at the door.

When she opened it, two Asian men were there. They said they were police officers calling about a burglary in the same road the day before.

Both men were wearing navy fleece jackets with blue police staff badges and showed handcuffs. The victim invited the men in. As they entered, two family members came down the stairs. One of them immediately became suspicious, recognising that police staff do not carry handcuffs. The men were challenged and asked to provide proof of identity.

The suspects were reluctant to do this and suddenly left the house, running along Kepple Road towards Burgess Road, before splitting up and heading in different directions.

Crime prevention officer Pc Andy Whitefield says: “If you do not recognise your caller, do not open the door.

“Public authorities representatives carry identification and will expect you to ask for it and take the time to check it.

“They are also happy to make appointments. If they do not have an appointment ask them to come back.”