The UK launched an investigation into how a fake bomb, disguised as a wedding cake box, was transported undetected on a UPS aircraft to Turkey earlier this month.
The package, which reportedly contained a timer, wires and a detector, was delivered to a UPS office in north London and flown to Istanbul, according to media reports.
A 26-year-old man was arrested in London on March 23 on suspicion of making a hoax bomb and was later released on bail.
After searching the suspect's home, police said the incident was not terrorism-related.
The UK Department of Transport said it is treating the matter "very seriously" and is looking at all aspects of the incident including UPS's procedures.
"Two weeks ago, a suspicious package traveled within the UPS network aboard an all-cargo aircraft from the United Kingdom to Istanbul, Turkey," UPS said.
The U.S. package delivery company said it is cooperating with the Department of Transport's investigation.
Last October, a bomb disguised as a printer toner cartridge was found on a U.S.-bound UPS plane at the UK's East Midlands airport.
The device had been timed to detonate over the eastern seaboard of the U.S., according to the police.
Another bomb was found in a U.S.-bound package at Dubai. In response, the UK introduced tougher security checks on air cargo shipments in transit from the Middle East, North Africa and south Asia.
-- Contact Bruce Barnard at email@example.com.