Authorities say a Texas mother with a drug debt to settle is accused of selling her seven-year-old son for $US2,500 ($3,387).

The Texas Department of Public Safety said that 29-year-old Esmeralda Garza of Corpus Christi was arrested last week.

Jail records did not list a lawyer for her.

The Corpus Christi Caller-Times reports a woman told investigators she bought the boy for $US2,500.

An arrest report says Garza said she and her boyfriend owed drug money and the child was given to the woman for $US500, the clearing of the debt and an additional $US700 when the "custody paperwork" was signed.

Child welfare agents executed a search warrant at a home in Nueces County and found the boy.

Authorities say Garza was also in the process of selling her two daughters, ages 2 and 3.