Justice Minister Somsak Thepsuthin has ordered the Corrections Department to investigate a warden at the Thonburi Women's Correctional Institute accused of corruption.
The guard allegedly demanded money from the family of a prisoner in exchange for preferential treatment.
Mr Somsak said the warden, who was not named, would be suspended during the investigation process and sacked if found guilty.
Mr Somsak's order came after Ronnarong Kaewphet, a lawyer, accompanied Pornpimol Suansamran, 31, on Thursday in filing a complaint against the warden with Wanlop Nakbua, deputy permanent secretary at the Justice Ministry.
Ms Pornpimol claimed the warden extorted money from her family by saying her jailed mother would be taken care of. She said she has been prevented from contacting her mother and was concerned about her safety.
Mr Ronnaraong said Ms Pornpimol presented evidence to prove her claim, including nine bank withdrawal receipts totalling 6,200 baht. She said her father usually handed the money to the warden at her house.
The warden allegedly told Ms Pornpimol that family visits to convicts were prohibited, despite department regulations allowing families to chat with inmates via video calls as a Covid-19 social distancing measure.
Ms Pornpimol said her mother used to be a motorcycle taxi rider before she was jailed in June last year after police found a bank account had been opened in her name and was used to receive money for marijuana dealers.
Her father contaced the prisoner through the video calls a few times before the warden then allegedly said these were now forbidden and extorted the money.
Ms Pornpimol claimed the warden promised to assign light tasks to her mother and take good care of her.
After the money was paid to the officer, she lost all contact with her mother as she was told the family could not even write due to further pandemic restrictions. Ms Pornpimol later discovered this restriction not to be true.
She said the warden's demand for another 10,000 baht was the last straw.
Ms Pornpimol also claimed the warden has tried to extort money from the families of other prisoners and that an ex-convict whose family faced similar demands would testify to that fact.
The Justice Ministry said Ms Pornpimol's mother could be transferred to another prison as requested by her family.