The drop in petrochemicals prices goes well beyond the fall in oil prices, suggesting that demand for plastics and synthetic textiles is extremely weak as the Asia-Pacific export- oriented nations, including China, suffer from reduced overseas orders.

The cost of naphtha – the cornerstone of the petrochemical industry – fell last week to a five-year low of $284 a tonne in the Far east Asia market, down 76 per cent from July's record high of $1,200 a tonne, according to Platts, the pricing agency.

At current levels, naphtha, a by-product of crude oil, is trading well below the cost of crude, a highly unusual phenomenon. While naphtha prices have tumbled more than 70 per cent in three months, oil prices had fallen 45 per cent – a gap that traders described as “unprecedented”.