Jakarta – Indonesian police have officially closed their investigation into the 1993 slaying of female labor activist Marsinah, which had sparked a controversy in the country and abroad after they failed to prove the latest evidence, an English-language newspaper said Tuesday.

The Jakarta Post quoted National Police chief Gen. Dibyo Widodo as saying that their last lead, a DNA test, failed because the blood sample, which was two years old when it was sent to Britain for investigation, had been contaminated.

"We are temporarily closing the investigation due to a lack of evidence," said Dibyo. "We sent the blood sample to Britain, but the laboratory could not use it for a DNA test because it had been contaminated."

The DNA test was the last and probably the only lead the police had to sustain their investigation into the murder which had stirred public outcry at home and abroad, the paper said.

Marsinah, a high school graduate, was found dead only days after organizing a workers' strike at a watch manufacturer in the East Java town of Sidoarjo, where she worked, demanding improvement in working conditions at the company.

Her badly mutilated body was found May 9, 1993, in an abandoned shack near the town of Nganjuk, also in East Java.

Her death sparked a huge controversy amid criticism that the government was dragging its feet with the investigation.

The trials of nine people – the owners, managers and security officers of the company – at a district court in the East Java provincial capital of Surabaja and the way they were arrested raised almost as much debate as the slaying itself, it said.

The Surabaja District Court subsequently convicted all the suspects for Marsinah's murder.

However, all nine of them had pleaded their innocence, and disclosed they had been interrogated under torture.

They also said they were framed for the murder because the government was taking so much heat from labor organizations and human rights campaigners at home and abroad, according to the paper.

In 1994, the Supreme Court acquitted the nine people, ruling the trials were inconclusive, and that much of the evidence was extracted from the suspects by force.

After their release, police insisted they remained the chief suspects and that the DNA test would support their cause for a new trial, the paper added.