A murder inquiry has been launched into the death of a 90-year-old woman who collapsed after being conned by thieves posing as water board officials.

Hester Mottershead died in hospital after being taken ill at her home in Tettenhall, Wolverhampton, on Friday afternoon, West Midlands Police said.

A police spokesman said inquiries were under way to trace three offenders who searched her home for valuables.

Officers believe three men, possibly wearing blue overalls, spent about 30 minutes at Ms Mottershead's home after she answered her door early on Friday afternoon.

The pensioner, who lives on her own, called police at 2.32pm and officers arrived within minutes, but she collapsed a short time later and was taken to hospital.

Although a post-mortem examination to determine the cause of death has yet to take place, officers are treating the investigation as a murder inquiry.

The men are described as in their late teens or early 20s, all wearing blue clothing. It is not yet known whether anything was taken.

Detective Inspector Andy Hawkins, leading the investigation, said: "We believe the offenders searched the whole house which would have taken at least half an hour.

"We are appealing for anyone who may have seen three people acting suspiciously in the area or the wider Tettenhall area during yesterday afternoon to contact us with information.

"Ms Mottershead's relatives will be supported by specialist family liaison officers and our thoughts are with them at this time."