The animal health wing of the US pharmaceutical giant Pfizer is being sued by a Chinese specialty veterinary medicine manufacturer after the company stopped selling its 3-Nitro anti-coccidial product in June following concerns over arsenic residues in meat.
Zhejiang Rongyao Chemical is claiming a breach of contract as the Chinese company had an exclusive multi-year agreement to sell Roxarsone, the active ingredient in 3-Nitro, to Pfizer subsidiary Alpharma.
Alpharma had sold 3-Nitro for a number of years and it has been used in poultry production for 50 years.
Recently, scientists at the US Food and Drugs Administration perfected a new method of detecting low levels of inorganic arsenic in poultrymeat, specifically in chicken livers, and discovered elevated levels in birds fed with 3-Nitro.
"The FDA's study was incomplete, non-peer reviewed and the results, therefore, are flawed. Further expert scientific review has found it inconclusive due to various inconsistencies," said Rongyao's general manager, Dr Rener Chen.
When the research was released, Pfizer and the FDA said 3-Nitro was not a danger to people consuming chicken, but the company decided to voluntarily halt sales.
Rongyao has claimed in the US District Court for at least $20m in lost revenues as well as for compensatory damages, interest, attorneys' fees, and any further amounts.
Pfizer accquired Alpharma when it bought US-based King Pharmaceuticals in May as part of the $3.6bn [£2.18bn] deal.
All arsenic-based animal health treatments are banned in the EU.