By Jonathan Kaminsky

(Reuters) - The American Civil Liberties Union has filed a federal lawsuit against a Mississippi county for holding detainees for close to a year without formal charge or access to an attorney, a lawyer for the group said on Wednesday.

The suit, filed on Tuesday in Jackson, names two plaintiffs but seeks class action status to include dozens more. It charges that Scott County, about 25 miles east of Jackson, has violated the U.S. Constitution by denying detainees a speedy trial, access to counsel and fair bail hearings.

"There has to be some sort of limit on how long a state can sit somebody in a box before they even bring formal charges against that person," said the ACLU's Brandon Buskey, lead counsel for the plaintiffs.

The two named plaintiffs, Octavious Burks and Joshua Bassett, have been held in the Scott County jail without formal charge for more than 10 and eight months respectively, the suit claims.

Burks, arrested last November for attempted armed robbery, had his bail set at $30,000, while Bassett, arrested in January for grand larceny and methamphetamine possession, had his bail set at $100,000, the lawsuit says.

Neither man was able to make bail, and both remain in jail without indictment or access to a lawyer, the lawsuit states.

Burks has spent over three years in the jail since 2009 on three separate charges, has been indicted once and has never stood trial or been convicted, according to the lawsuit.

Felony suspects arrested in Scott County often make their initial appearance before a judge with only the arresting officer present, with bail set without lawyer input and with no opportunity for the suspect to contest the charges in a preliminary hearing, Buskey said.

Detainees are then held at the county jail until a grand jury convenes, which in Scott County occurs three times per year, and decides whether to indict them, Buskey said.

The ACLU estimates that some 50 people are being held in the Scott County jail pending indictment and without access to a lawyer for an average of three or four months.

In addition to the county and two judges, the Scott County Sheriff and District Attorney are named as defendants. Neither immediately returned messages seeking comment.

(Reporting by Jonathan Kaminsky in New Orleans; Editing by Sandra Maler)