Police investigating the disappearance of Madeleine McCann were last night interviewing a man as they searched a villa 160 yards from where she was snatched.

Intense police activity surrounded the house lived in by British man Robert Murat.

His mother, Jenny, who is believed to own the house, has been running a stall on the seafront in the village of Praia da Luz, Portugal, appealing for information from members of the public about the four-year-old.

Mr Murat was a regular sight, crossing the police tape and approaching the McCanns' apartment following Madeleine's disappearance. He said he was helping the McCanns as a translator.

But journalists told police earlier this week that they had suspicions about him.

The Policia Judiciara confirmed last night that they were questioning a man. A spokesman for the investigation did not confirm the nationality or identity of the person and described it as a "normal development".

On May 4, the day after Madeleine's disappearance, when media descended upon the area, Mr Murat made himself known to journalists, chatting about the case, but initially refusing to reveal what his role was.

He told people that he had a daughter the same age as Madeleine.

A few days later, Sunday Mirror journalist Lori Campbell reported him to the Portuguese police because she thought he was suspicious.

She said: "He surfaced on Friday afternoon last week and was walking around as if he was somebody official. He claimed that he was just a local guy who spoke fluent Portuguese and English and was helping the family.

"He was coming in and out of the family apartment, speaking with the media and acting like he was somebody official. But when questioned about it, he was very vague about his position.

"He said he just volunteered to help the police with their investigation.

"He was in and out of their apartment throughout the week. He said he was just helping to translate witness statements.

"When I was talking to him he was very vague about his purpose. He said he was from the UK going through a divorce back there.

"Asked about what he did for a living, he said he was a property developer, real estate.

"He kept trying to emphasise parts of the investigation such as 'maybe she's gone to Spain, maybe it's too late'."

It is understood the search of Mr Murat's villa started at 7am yesterday and has included draining its swimming pool.

Local translator Gaynor de Jesus, 32, who went to school with Mr Murat, said she was "shocked" at the development. She said he had joked with her about media rumours that he was a suspect in Madeleine's disappearance.

Ms de Jesus told Sky News: "I do know that he has been the official translator for the police. All witness accounts, everything that's been coming into them, he has had first-hand information."

Dave Shelton, a local expatriate Briton who organised volunteer searches in the area since Madeleine's disappearance, had been due to help organise Mr Murat's mother's stall in the town. The idea was to gather information from people who otherwise might be unwilling to speak to police.

Madeleine was snatched from her bed on May 3 while her parents, Gerry and Kate, from Rothley, Leicestershire, were dining in a tapas bar opposite their holiday apartment.

All last night's activity took place only about 200 yards from where the McCann family is now staying.

Mr Murat's cousin, Sally Eveleigh, said there was "absolutely no way" he could have anything to do with Madeleine's disappearance. She agreed that his daughter looked very like the missing girl, but added that lots of children could look similar to her.

Ms Eveleigh, who runs a guesthouse near Lagos, close to Praia da Luz, told Sky News: "They (police) had heard from English reporters that this was happening, that Robert had said he missed his daughter so much.

"And from that, because they've got nothing to go on, they've all started assuming."

Mr Murat lived in the village of Hockering, Norfolk, with his ex-wife Dawn, before moving to Portugal about two years ago, local residents said.

Geoffrey Livock said he had a daughter due to start school this year, and returned to the house periodically.

"I last saw him working in the garden a few weeks ago," Mr Livock said.

"Dawn, his ex-wife, said he was doing some interpreting work in Portugal."

He added that Mr Murat worked at a Bernard Matthews poultry farm before he left the UK.

Two women, each carrying a child in a blanket, emerged from the house in Hockering where Mr Murat's ex-wife lives shortly after 10pm last night. They were driven away by police.

A Norfolk Police spokesman said: "We have responded to the situation as it has developed." He added that no one had been arrested at the address in Hockering and no one in the village was being questioned.

Earlier, Madeleine's family said they "can't even consider" leaving Portugal as they lead an international effort to recover their abducted daughter.

They thanked friends, family and the public for their efforts to get back their daughter, whose fourth birthday was on Saturday.

"As far as we are concerned, until there is concrete evidence to the contrary, we believe that Madeleine is safe and being looked after and that's how we can continue in our efforts," Mr McCann said.