A bogus caller stole money from an elderly woman in Hove on Tuesday (14 February).
The man called at the home of a woman in her eighties in Downland Drive in Hangleton at about 4.25pm.
He said that he was from the water board and that a pipe had burst further down the street and he needed to come in to turn off the water.
The woman let the man into her home and stayed with him while he went into the kitchen.
When he left about 20 minutes later, the woman realised that money had been stolen from the property and called police.
The man was described as white, about 5ft 5in tall, of slim build, clean shaven with short dark hair and in his late twenties or early thirties.
About an hour later a similar scam led to a woman in Crawley having money stolen from her home.
Sussex Police said that officers were considering whether the two incidents were linked.
The bogus caller in Crawley also said that he was from the water board and that a pipe had burst.
A woman in her eighties let the man into her home in Gossops Drive.
After he left she found that money had been taken and she called the police.
The man was described as white, about 5ft 10in tall, of skinny build and clean shaven. He was wearing a navy blue v-neck sweater and dark blue trousers.
A Sussex Police spokesman said: “We believe that on both occasions the caller was distracting the resident while an accomplice let themselves into the property through the front door which may have been left ajar and then searched for money.
“I would advise everyone not to keep large amounts of cash in your house and not let anyone into your property if they are not expected.
“Always check someone’s ID and keep the security chain on while you are doing so.
“If you are in doubt, don’t let them in and phone the company they claim to be from using a phone number from a telephone directory
“If you are suspicious then call police on 101.”
Anyone with information about these incidents is asked to contact Sussex Police on 101 or the independent charity Crimestoppers anonymously on 0800 555111.