A Mexican official says troops have detained 15 federal police officers for allegedly kidnapping the owner of a construction company in the northern border city of Matamoros and demanding a $2 million (31 million peso) ransom.

An official with the federal Attorney General's Office says the officers were arrested late Thursday as they prepared to receive the money they demanded for earlier releasing the businessman. The official agreed on Saturday to reveal details of the case only if not quoted by name, because he wasn't authorized to talk with journalists.

The official says the officers face charges of kidnapping and extortion.

The arrested officers are part of a group sent this year to bolster a security operation in Matamoros, which is across from Brownsville, Texas.