Operations were cancelled and theatres shut when bugs were discovered in a hospital.

The tiny intruders caused chaos when they were spotted flying around sterile areas at Worthing Hospital.

They appeared to be dropping from the ceiling of the operating theatres, sparking fears they had managed to breach the ventilation system.

Some of the insects were dispatched with a spray called Canned Death while others were caught so they could be studied more closely.

The 6mm creatures turned out to be weevils, a type of beetle and a common garden pest.

A team of investigators, including consultant microbiologist Jenny Child, discovered the bugs had made their entry through open office windows nearby.

That came as a relief because the theatres' ventilation system is extremely complex.

Air sucked in from outside passes through a series of increasingly fine filters until it is virtually free of any kind of insect.

It is adjusted to the right temperature and humidity, then piped into the theatres.

If the creatures had made their way in that way, lengthy repairs could have been necessary.

Investigators spent two hours searching the roof space for evidence of infestation after the ventilation system was found to be intact.

The theatres were shut for several hours and given a thorough clean as a precaution.

The postponed operations were rescheduled.

A hospital spokeswoman said: "We have managed to resolve the problem now but clearly we do not want this to happen again.

"We are keeping the office window shut while we try to work something out. You have to be extra careful in sterile areas, which is why the area was closed.

"We have never had a problem like this before. We are not sure why the bugs appeared although we have heard reports of similar infestations along the coast."