Two weeks after the disappearance of Madeleine McCann in the Algarve, Portuguese police admitted this evening that they still do not have enough evidence to make an arrest.

At a news conference in Portimao, the provincial town close to the village of Praia da Luz, where Madeleine was last seen on the night of May 3, Olegario Sousa, the detective leading the investigation, said the latest man interviewed by police was not regarded as a suspect.

"To this moment we do not have enough evidence to arrest anybody," said Mr Sousa, the day after a Russian website designer was questioned by police because of his alleged links to Robert Murat, the British father identified as the only suspect in the case so far.

Mr Sousa said that several items had been seized from the home of Sergei Malinka, 22, who is believed to have had several telephone conversations with Mr Murat around the time of Madeleine's disappearance two weeks ago.

But he conceded that Mr Malinka remained a witness in the case. He also dismissed reports in the Portuguese press today that police were investigating a sighting of a girl similar to Madeleine in a red car in southern Lisbon. Mr Sousa said the focus of the inquiry remained in the Algarve.

Earlier today, Mr Malinka said he had been ruined by his involvement in the investigation even though the computer equipment seized from his home was returned today after police found no incriminating evidence.

Mr Malinka, who lives with his parents just 500 yards from Madeleine’s holiday apartment, said: “My telephone number was on Mr Murat’s mobile phone.

"Everybody on his telephone has been spoken to. But I can’t comment on telephone calls. I’ve invested seven years of my life in this country trying to succeed and suddenly in one hour it’s all fallen apart.” Mr Mr Malinka he was “completely” innocent and had no criminal record in any country.

It is believed detectives asked Mr Malinka about a tour company he was involved with at Lagos Marina, five miles from Praia da Luz, which organised boat trips to the Mediterranean and North Africa.

Detectives have searched the records for yachts which visited Lagos after receiving reports of girl resembling Madeleine being dragged down to the Marina. Posters appealing for information about Madeleine have been printed in Arabic after fears that she may have been smuggled to Morocco, Algeria or Tunisia.

Meanwhile, Madeleine's parents have said that working on the new campaign to find their daughter has helped them to escape “dark places” they entered after her abduction.

Kate and Gerry McCann have been coordinating the Find Madeleine campaign to spread the image of their missing daughter and to help organise an international hunt.

The campaign’s website received five million hits in the first 24 hours since its launch on Wednesday afternoon.

Mr and Mrs McCann, from Rothley, Leicestershire, have stopped watching the almost constant television coverage in Portugal of the hunt for their daughter as they work with British lawyers and family members on the campaign.

Michael Wright, a relative of the McCanns, said that the work had helped them avoid “a return to the dark places they might have been in the early days”.

Speaking outside the apartment in Praia da Luz, where the McCanns have spent the waiting for news of Madeleine, Mr Wright said the couple had been overwhelmed with offers of support. He said a cash fund would be used to pay for the campaign and engage experts both in publicity and the detection process itself.

Although primarily aimed at Europe, it could also spread to North Africa across the sea from the Algarve.

“Gerry and Kate are taking immense strength from the support and good wishes that they are receiving from all over the world,” said Mr Wright. “They have been totally overwhelmed by offers from individuals, small companies, and large multi-national corporations.

He said: “We want to make sure that if Madeleine isn’t in Portugal that the rest of Europe is aware of the image of this little girl. Our target is to reach the saturation that we know has been achieved in the UK and certainly in the Algarve.”

Mrs McCann, a GP, had earlier attended an Anglican service at the church in Praia da Luz. She was accompanied by a small group of friends and family, including Father Paul Seddon, the priest who married the McCann’s and baptised Madeleine.