A leaking package at an Amsterdam postal delivery service on Wednesday did not contain the nerve toxin ricin, officials said in the afternoon.

Six workers were taken to hospital with breathing problems after being exposed to fumes from what was thought to be a broken bottle of ricin.

However, according to broadcaster Nos, the bottle probably contained an oil. This may have been castor seed oil, also known as as rincini oil. The package itself contained a number of different bottles.

Nevertheless, it is unclear why the six workers developed breathing problems.