A 19-year-old construction worker is in custody after four masked men robbed a family of four at gunpoint at Goed Fortuin, West Bank Demerara, early on Friday, Police said.

Police said the robbery occurred at about 12:05am, when the suspects, one armed with a handgun, approached a 53-year-old woman on the verandah of her home and threatened her.

She raised an alarm, and her 62-year-old fisherman husband went to investigate. The suspects then entered the house, ordered the occupants to lie on the ground and demanded cash, according to Police.

The couple's 25-year-old son was struck on the forehead with the firearm after he tried to resist. He was taken for medical attention. The couple's other son, 27, was also in the house.

The suspects escaped on foot with $315,000 in cash and two Samsung Galaxy cellular phones.

Acting on information, Police arrested the 19-year-old, of Goed Fortuin, in connection with the incident. He remains in custody as investigations continue.