Mexican drug trafficker Joaquin Guzman Loera aka 'el Chapo Guzman' (C), is escorted by marines as he is presented to the press on February 22, 2014 in Mexico City.

Federal prosecutors on Tuesday asked a judge to sanction lawyers for accused Mexican drug lord Joaquin "El Chapo" Guzman because his wife allegedly used a cellphone in the New York courthouse where he is on trial.

Guzman has previously twice escaped custody in Mexico.

Prosecutors claimed in a letter that an unnamed person or persons "appear to have used cellular telephones in concert with an attorney visit to the defendant following two trial days last week to facilitate unauthorized and [under special security rules] impermissible contact between" Guzman and his wife, former beauty queen Emma Coronel Aispuro.

U.S. Marshals at the federal courthouse in Brooklyn, in reviewing security footage from Nov. 19, "observed Ms. Coronel using a cellular telephone inside the courthouse," said the letter to U.S. District Judge Brian Cogan. That was a day after courthouse staff "had observed Ms. Coronel using a cellular telephone inside the courthouse."

Prosecutors noted they had mentioned the use of that phone during sidebar conferences with Cogan and defense lawyers at Guzman's trial Monday, out of earshot of the jury in the case.

Cellphones are not allowed to be brought into that courthouse beyond the security screening area by individuals who are not lawyers or are authorized to carry electronic communication and recording devices.

Cogan earlier this month had rejected a request by lawyers for the escape-prone Guzman to allow him to give Coronel a brief hug before his trial began.