By Michael Holden

LONDON (Reuters) - A British detective heading an investigation into the disappearance of Madeleine McCann, who vanished while on holiday in Portugal six years ago, said new evidence suggested the British youngster was snatched in a planned abduction.

McCann, then aged three, disappeared from her family's apartment at the Praia da Luz resort in the Algarve in May 2007 while her parents dined with friends at a nearby restaurant.

Her disappearance sparked a global search that gripped the world's media but, despite extensive appeals, her fate remains a mystery and a Portuguese police inquiry closed five years ago.

On Monday a British team of detectives, who began a new investigation in July, said they pieced together a new sequence of events suggesting Madeleine was targeted by abductors.

They said they wanted to trace a number of men, including some thought to be either Scandinavian or German, while another line of inquiry is she was taken after disturbing burglars.

"Madeleine McCann's disappearance does, on one reading of the evidence, have the hallmarks of a pre-planned abduction," Detective Chief Inspector Andy Redwood told BBC's "Crimewatch" program which broadcast a new reconstruction of the events.

Redwood said the Portuguese inquiry centered on a dark-haired man seen carrying a child by Jane Tanner, one of the McCanns' friends, near their apartment on the night she vanished.

But Redwood said his team had ruled this man out and was keen to trace another man spotted about 45 minutes later by an Irish family holding a child matching Madeleine's appearance and heading towards a nearby beach.

"This could be the man who took Madeleine," Redwood said. "It is vital that we identify who he is."

Police have released two e-fits of this man, as well as artist impressions of other men seen near the McCanns' apartment in the days and hours running up to Madeleine's abduction.

SUSPICIOUS BLONDE-HAIRED MEN

One witness saw a fair-haired man near the apartment twice, while an hour after Madeleine was reported missing, two blonde-haired men were seen nearby acting suspiciously.

"We have got some suggestion from the witnesses that we've spoken to that possibly they looked Scandinavian, or were possibly talking in German or Dutch," said Redwood, adding they had approached police in Germany and the Netherlands to see if were aware of any known offenders who might be relevant.

A TV appeal will also be made in the two countries.

Redwood said another strand of the investigation related to a four-fold increase in burglaries in the area at the time.

Madeleine's parents Gerry and Kate were themselves named as formal suspects by Portuguese detectives four months after her disappearance, but in 2008 they were cleared and Portugal's public prosecutor dropped the case, citing a lack of evidence.

Kate McCann told "Crimewatch" that she had persecuted herself for years over the decision to eat out that night.

"But ultimately it's not us that's committed this crime. It's the person who's gone into that apartment and taken a little girl away from her family," she said.

Despite the huge media interest triggered by the new appeals, Mark Rowley, who heads London's Specialist Crime and Operations division, poured cold water on suggestions that arrests or breakthroughs were imminent.

"This isn't about to reach a conclusion. There's an awful lot of work to do," said Rowley.

(Editing by Belinda Goldsmith and Mike Collett-White)