They claim they have been incarcerated simply because they happened to have been with the wrong people at the wrong time.

The women are among more than 7,000 convicted criminals and people facing charges who say they have done nothing wrong.

The Justice Ministry has agreed to reinvestigate their cases.

This is not the first time that judicial officials have been forced to re-open cases where serious doubt exists.

One of the most high profile cases of recent years involved the murder of Sherry Ann Duncan in 1986. Four construction workers were accused of killing her, but many years later they were exonerated after the case was re-opened in a blaze of publicity.

"Noi", 22, is among 561 individuals the ministry believes may also have been wrongly charged.

In November 2005 she was accused of possession of methamphetamines with intent to sell. She was having a meal with her boyfriend when arrested.

"We met a while ago and I had no idea he was a drug dealer," she said.

Her boyfriend told police Noi was not involved in dealing but she was still arrested and charged.

"I've been on remand for one year now and I wonder how I'm going to get out because I'm innocent, yet I know I'll be in this jail for years to come until my trial ends," she said.

The ministry reinvestigation means she has a chance to prove her innocence. She has witnesses to back up her story.

"Bee", 21, is awaiting trial for possession of 91 vials of the psychedelic drug ketamine.

She was arrested with her boyfriend of two months who told her he was a paper supplier.

"He pleaded guilty. I deny the charge. I told police I'd only just met the guy but they didn't believe me," Bee said.

 "The reinvestigation will give me a chance to prove my innocence and has raised my hopes to be freed," she said.

Another inmate, 25-year-old "Pat", is on appeal for a 2004 conviction for possession of methamphetamines with intent to sell. She was arrested while travelling in a friend's car in which 100,000 pills were discovered.

"I'd no idea he had drugs in his car. We were on our way to shop for his kids," she said.

"I've been in jail for two years. I just want to go home to my family and never come back again," Pat said.

Corrections Department director-general Nathee Chitsawang said it would reinvestigate 7,206 cases. Of those, 3,943 involve convictions and the rest are either on trial or awaiting trial. Most are concerned with drug offences.

The cases have been divided into four groups. Group A is classified as having a "strong suggestion of innocence", while Group B involves cases where there is conflicting evidence.

Those who may not have received a fair trial make up Group C.

The majority - 4,200 cases - are in Group D, comprising convicted offenders seeking legal assistance for appeal.

The department will collect documentary evidence and interview those involved before submitting promising cases for a second round of screening, Nathee said.

He said a court had already dismissed charges against one of the people.

For wrongful convictions, the department can seek royal pardons, Natthee said.

Justice Ministry deputy permanent secretary Kittipong Kittiyarak said only 3 per cent of prisoners were seeking to have their cases re-examined.

Anan Paengnoy

The Nation