Sakhon Kamto, 24, was released on Tuesday after being detained by police for questioning over the much publicised kidnapping of an infant girl from Lop Buri Hospital last Friday. Her mother Amporn, 50, was suspected to be an accomplice.

Lop Buri police, however, said they would ask Sakhon to return so that six hospital staff who witnessed the crime can determine whether or not she was the kidnapper. Closed-circuit cameras in the hospital filmed the kidnapper.

Sakhon and her mother, who had a bruise on her chin, met reporters in her hometown in Udon Thani yesterday.

Sakhon said she and her mother were apprehended on Monday and brought to a police station where they were questioned in separate rooms.

"Police threatened me to confess I kidnapped the baby," she said. Her initial confession was made under duress and because she was afraid her mother would be jailed.

After the lengthy interrogation, officers drove Sakhon to Lop Buri.

"Along the way, a fat, white policeman kept threatening me, slapped me across the face four times and pulled my hair," she said.

"When I refused to plead guilty, he punched me in stomach and slapped me across the face with a shoe," Sakhon said. "I was so frightened."

She was later released after witnesses failed to pick her from a line-up. Police then deposited her and her mother at Saraburi train station, gave her Bt1,000 and warned her not to tell anyone what had happened.

After consulting with relatives, however, she decided to file a complaint against the women and children's protection division of the police, which is overseeing the case.

Sakhon and Amporn have asked to be put under the protection of the Pavena Hongsakul Foundation for Children and Women.

Maj-General Kamronwit Thoopkrajang, commander of the women and children's protection division denied Sakhon's accusation. She confessed to kidnapping the infant and dumping her in a stream, but police found this was false after checking out her confession, he said.

Following Monday's interrogation, police said they believed Sakhon had disguised herself as a hospital worker in order to kidnap the younger of the newborn twins.

The twins were born to Ratree Trakanchan, 22, with whom Sakhon's husband had had an affair.

Sakhon and Suprot Khanthongdee, 29, became involved when they worked together at a sandwich factory in Chon Buri, police said.

Kamronwit said Sakhon was still a suspect even though she had been released.

Colonel Thanyasit Amornsukhon, superintendent of Lop Buri's Muang police station said Sakhon and Amporn were still considered suspects in a conspiracy to kidnap and both would have to return for another line-up as soon as possible.

However, Kamronwit said it was also possible the baby was kidnapped by a trafficking gang.

Officers also discovered Suprot had had affairs with other women and one of them could have been the kidnapper.

Police have asked professionals to produce a clearer photograph of the kidnapper from the hospital's closed-circuit cameras.