Four conmen barged into the home of an 85-year-old woman and stole her £25,000 life savings while her bedridden son called out for them to stop.

Police believe the theft, which they have called "sickening", could be related to a string of similar robberies across Sussex in the past two months.

The woman, who is disabled and relies on two walking sticks to move around, answered the door to four men who claimed to be from the water board.

When she questioned them they said they were police and forced their way into her home in Coombe Road, Brighton.

They split up and searched the upstairs and downstairs of the property.

One of the thieves went into the lounge, where the woman's sick son was lying.

The man, in his 60s, was powerless to stop the thief from searching his mother's handbag where he discovered the £25,000 in a clear envelope. They also stole clothing and a camcorder.

Details of the burglary emerged yesterday after police discovered further details of the incident, which occurred on December 11 at 8pm.

The victim initially told police £200 had been stolen but when they returned to carry out a routine welfare check she revealed the true figure was £25,000.

She told officers she had been too embarrassed to admit the real amount.

One man is described as of big build and between 25 and 30.

Another is about 5ft 6in with spiky hair. The victim told police she thought they all had local accents.

Detective Constable Gary Pullen said: "To target someone who is so vulnerable is sickening. The fact that they have stolen all her savings, her and her family's future, I can hardly begin to put into words how that makes me feel.

"The whole ordeal has left a determined lady very, very frightened in her own home."

A Sussex Police spokeswoman said: "The lady had been saving her money up. Sometimes it is hard for the elderly to go to and from the bank with money.

"These thieves made a quick getaway.

It is impossible to know why they targeted her.

Perhaps they had visited months earlier and realised she was vulnerable."

The police major crime branch is investigating a series of burglaries in Sussex which began on November 14 at Gun Hill, Chiddingly.

Between November 21 and 27, the gang struck three times in Crawley Down, Laughton and Chelwood Gate.

They most recently struck on December 27 in Upper Horsebridge.

All the burglaries were carried out by four or five men who forced their way into the elderly victims' homes and took cash and jewellery.

Violence was used during some of the burglaries but no one has been seriously injured.

A Sussex Police spokeswoman said: "We are not ruling out the possibility these could be linked."

It is estimated there is one bogus caller incident in Brighton and Hove every week.

Last week, The Argus reported two homes in Hove and one in Lewes were targeted by burglars posing as water board employees.

On January 10, a man entered a property in Storrington Close claiming to need to inspect taps and took a purse from the homeowners bedroom.

At about 8.30pm, two men claiming to be from the water board stole a locked red money box from a home in Ingram Crescent.

On the same night a bogus caller claiming to be from the water board stole cash and cutlery from a home in Highdown Road, Lewes.

louise.acford@theargus.co.uk