An aide to Rep. Henry Cuellar and Grayson  Prestona political and business consultant have agreed to plead guilty to conspiring to help the Democratic congressman from Texas launder more than $200,000 in bribes and to assist prosecutors in a federal criminal investigation, according to court documents unsealed this week. 

Federal court records show Mina Colin Strother, Cuellar's former congressional aide, and Florencio "Lencho" Rendon, a political and business strategist, entered guilty pleas in March. Rendon and Strother both pleaded guilty to conspiracy to commit money laundering, facing up to 20 years in prison and up to five years in prison, respectively, and fines. Their plea deals also guarantee their cooperation in the Justice Department's investigation into Cuellar and his wife.  

The San Antonio Express-News first reported the guilty pleas. 

Cuellar and his wife, Imelda Rios Cuellar, have been indicted on more than a dozen charges alleging they accepted close to $600,000 in bribes from a Mexican bank and an oil company owned by the government of Azerbaijan, in exchange for promoting the bank and energy company's interests. Federal prosecutors allege the bribes were laundered in the form of sham consulting contracts through front companies and middlemen into shell companies owned by Imelda Cuellar. The congressman's wife, according to the indictment, "performed little or no legitimate" work under the consulting contracts.

Rendon knew the contract was a "sham consulting contract" and that the payments of $15,000 per month were made to funnel money to Cuellar, Rendon's plea agreement said.

Rendon would send $11,000 a month to Strother, who would in turn transfer monthly payments to the Cuellars of $10,000. From March 2016 to February 2018, Strother transferred nearly $215,000 to the Cuellars, according to court filings. 

The Cuellars have pleaded not guilty, and were released on an unsecured bond. Cuellar has publicly insisted on his innocence. 

— Rob Legare and Melissa Quinn contributed to this report