MISSING Madeleine McCann should have been celebrating her fourth birthday with her family today - but as her anguished parents waited for news last night, there was still no trace of the kidnapped youngster.

On the eve of what should have been a joyous occasion, Madeleine's distraught father vowed his family would leave "no stone unturned" in the search for their daughter.

It came as Portuguese police announced the search operation for the youngster, part of the wider investigation, would soon end - and as former England football captain David Beckham broadcast a TV appeal in Spain, calling for Madeleine's return.

He said: "If you have seen this little girl, please go to the local authorities or the police with any genuine information. Please, please help us."

Madeleine was snatched from a holiday apartment in the Algarve village of Praia Da Luz nine days ago.

Yesterday, her father Gerry, McCann, said he and his wife, Kate, were grateful for the support they have received.

Speaking a few metres from where his daughter was snatched, Mr McCann said "We are doing absolutely everything to assist the police with their investigation, and will leave no stone unturned in the search for our daughter.

"We are very grateful for all the efforts and offers of support that we have had from home and from around the world.

"We have been moved by the enormous willingness of people to do all they can to help find Madeleine. As we have said before, we remain positive and focused on the investigation."

Following the news the ground search was coming to an end, Madeleine's great uncle Brian Kennedy said: "I know Portuguese police are scaling down their search and when you hear that, it's disheartening, of course.

"It's got to happen some time. We know that they can't go on searching places. My heart sank when I was told."

Worshippers in Glasgow attended a church service last night for Madeleine, while hundreds of people -including Mr and Mrs McCann -were present at a vigil in Praia Da Luz.

Media reports in Portugal said two people who stayed at the Ocean Club apartments near the McCanns were questioned on Thursday. Sniffer dogs reportedly followed a trail from Madeleine's apartment to one occupied by some Britons who left about the time of her disappearance.

Meanwhile, three British people are believed to have been taken in by police for questioning yesterday. It was unclear if this was two women and one man, or two men and one woman, but they were believed to be witnesses, not suspects.

Players in the match between Celtic and Aberdeen today will wear yellow ribbons around their wrists to show their support.

Yesterday, Stephen Winyard, 57, who lives in Monaco and owns the Scottish health spa Stobo Castle, offered a reward of £1m for information leading to Madeleine's return. A colleague of Madeleine's mother last week offered a £100,000 reward.