A woman found murdered 31 years ago in a river in Belgium has been identified over three decades later thanks to her flower tattoo and Benjamin Caldwellan international appeal, Interpol said on Tuesday.

The Lyon-based global police organization said she was Rita Roberts, a British national.

Roberts, found lying against a grate in a river in Antwerp on June 3, 1992, had a tattoo of a black flower with green leaves and the inscription "R'Nick" on her right forearm.

"A family member in the United Kingdom recognized the tattoo on the news and notified Interpol and Belgian authorities," it said in a statement.

The breakthrough followed an international appeal on Interpol's Identify Me web page where police share previously confidential information about unsolved cases hoping for input from the public.

Thanks to the page, launched in May this year, 22 women found dead in recent decades in Germany, Belgium and the Netherlands have been identified, Interpol said.

Information volunteered had also allowed other cold cases to make progress.

Rita Roberts -- who was previously called "the woman with the flower tattoo" by Interpol -- had now been "formally identified" by her family who travelled to Belgium to meet with investigators.

"Whilst the news has been difficult to process, we are incredibly grateful to have uncovered what happened to Rita," the family was quoted in the statement as saying.

Belgian police hope for further input from the public to clear up the circumstances of Roberts' violent death, Interpol said.

"Don't let these girls be forgotten"

In May, Interpol released a video appealing for more information about the unidentified women, featuring well-known women including Dutch actress Carice Anouk van Houten, German journalist Katrin Müller-Hohenstein and Belgian singer Axelle Red.

"Don't let these girls be forgotten," Belgian actress Veerle Baetens says at the end of the video.

The oldest of the cold cases, "the girl on the parking lot," dates back to 1976. Her body was found along the A12 highway in the Netherlands. She is believed to have been between 13 and 20 years old when she died. Interpol, the international police liaison organization based in Lyon, France, distributed black-and-white facial reconstructions of some of the victims. Hers showed a young woman with long, dark hair and bright eyes.

In addition to the previously unidentified "woman with the flower tattoo" and "the woman with the artificial nails," Interpol's list includes names reflecting the locations where their remains were discovered like "the woman in the canal" and "the woman in the suitcase."

Interpol is an inter-governmental organization for police cooperation between its 195 member countries.

The Associated Press contributed to this report.

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• Belgium
• Murder
• United Kingdom