Lagos customs chief Haruna Mamudu said the fake rice was intended to be sold in markets during the festive season.

He said the rice was very sticky after it was boiled and "only God knows what would have happened" if people ate it.

It is not clear where the seized bags came from but rice made of plastic pellets was found in China last year.

Rice is the most popular staple food in Nigeria.

The BBC's Peter Okwoche says it is the only foodstuff that crosses cultural and ethnic lines across the country.

Investigations are under way to establish how much of the contraband has already been sold.

The customs official called on "economic saboteurs who see yuletide season as a peak period for their nefarious acts to desist from such illegal" business activity.

Mr Mamudu did not explain how the plastic rice was made but said it had been branded as "Best Tomato Rice".