Air safety investigators are checking claims that an aircraft dumped fuel over a Devon town after a series of complaints about acrid fumes.
Some Ottery St Mary people felt sick and the post sorting office was closed as people were overcome by the smell.
The town is five miles from Exeter Airport but no aircraft have reported dropping fuel.
The Civil Aviation Authority (CAA) said fuel dumping was rare and should be carried out over sea at high altitude.
Headache complaints
Lynn Swaffield-Williams said she was sickened by the smell on Wednesday morning, which she and other residents suspected was aeroplane fuel.
She said: "I had never smelt anything like it. It made me and my 10-year-old daughter feel really sick for a couple of hours."
Sub postmistress Sharon Fabry, who had to evacuate the building because of the smell, said: "Children were moaning about feeling ill and a couple of people said they could not get rid of headaches all day."
The CAA, which is checking aircraft logs, said it would be notified if any aircraft dumped fuel.
A spokesman said: "The only reason would be an emergency.
"If a plane is too heavy it cannot land safely."
Wales and West Gas, who checked the area, ruled out a gas leak.
A spokesman said: "In the past this has happened when aircraft have offloaded fuel before landing.
"If the winds are strong vapour can be carried inland resulting in a similar smell to gas."
Spokesmen at both Bristol and Exeter Airports said no aircraft had discharged fuel.
Source: BBC