Police are growing "increasingly concerned" about a missing and vulnerable 73-year-old woman.
Pauline Lake, of Birdhurst Gardens, South Croydon, has dementia and type 2 diabates and has not been seen since 7pm yesterday.
She told her husband she was going for a walk but did not return.
Police said Mrs Lake's mental health had "dramatically worsened in the last few weeks" and her disappearance yesterday is second in three days.
The first time she went missing, on April 13, she was located in Northamptonshire. She had no known links to the area and is believed to have travelled there at random.
Mrs Lake is white, 5ft 2ins tall, slight and has short grey hair. She is believed to be wearing a short-sleeved grey top, black trousers and green-blue fleece and carrying a black shoulder bag.
She is thought to be carrying a Freedom Pass and be competent using the transport system.
Police asked anyone with information to call Croydon Missing Persons Unit on 0208 649 0016 or Missing People on 116000.
- Pregnant woman subjected to 'threatening and disgusting abuse' on Southern train
- Man critically injured in Thornton Heath stabbing
- Man dies in hospital after crashing car into a tree
- Croydon Tramlink suspended after early morning house fire - lines now re-opened
- Tube workers vote on strike action in dispute over sacked colleague