South Yorks sniffer dogs in 'Maddie' hunt

Specially-trained South Yorkshire Police springer spaniels Eddie and Keela were reportedly flown to Praia da Luz in the Algarve last week to take part in the investigation.

And it is understood the new clue was discovered by the team led by Sheffield-based South Yorkshire Police officer Pc Martin Grime, one of the world's top sniffer dog handlers.

Pc Grime works with specially-trained springers who can sniff out the smallest samples of human blood, even after items have been cleaned or washed many times.

The dogs, which were brought up in Doncaster, were called in to help after police looking into Madeleine's disappearance re-focused inquiries on the McCanns' holiday apartment.

Madeleine has now been missing for 99 days and police are increasingly desperate for any kind of breakthrough in her case - as are her parents Kate and Gerry, who are still in Portugal.

Eddie and Keela are attached to South Yorkshire Police and are trained to locate traces of blood to help officers in murder and missing person inquiries.

Eddie is a "victim recovery dog" which can detect blood and human remains, while Keela has been trained only to detect human blood and specifically very small samples.

It appears highly likely she was the dog brought in by British detectives last week which located tiny traces of blood in the McCanns' apartment.

Police are still waiting for the results of tests on the recovered traces, which arrived yesterday at a top UK forensic laboratory.

The dogs, which command 1,000 a day for their first class skills, have worked on several high-profile murder cases in the UK and abroad, helping solve recent crimes and incidents up to 25 years old. Keela worked on the attempted murder of young mum Abigail Witchells in Surrey in 2005, and has even been to America to demonstrate her skills to the FBI. Eddie located the body of pensioner Attracta Harron in a shallow grave in County Tyrone in April 2003 after the 65-year-old was murdered on her way home from mass.

Her killer, Trevor Hamilton, 23, was put behind bars last year for the murder - which was committed less than four months after he completed a sentence for rape.

As well as locating the pensioner's body, the seven-year-old dog found the murdered woman's blood on Hamilton's burned-out Hyundai.

A dog diary about Keela on the South Yorkshire Police website written when she was six months old says she and Eddie live "with my dad" at home in Doncaster.

It reads: "He is going to train me to search for very small spots of blood at crime scenes, so small that the humans can't see it.

"My very sensitive nose will be able to smell the blood and I will show Dad where it is. He can then show the scientists so that they can take samples."

South Yorkshire Police were unavailable for comment.