Kate McCann is "upset" at a decision by police to invite her and Gerry back to Portugal to take part in a reconstruction, a friend of the couple said.

Portuguese police have invited the McCanns to participate in a reconstruction of the night Madeleine vanished from their holiday apartment in the resort of Praia da Luz on May 3 last year.

It is not known whether friends who were on holiday with the McCanns, other holidaymakers and staff working at the resort will also be invited to take part in the reconstruction.

The friend of the McCanns said: "Kate is upset. There's been no sense of concern for her feelings or the anguish it will cause her. On an emotional level she is not sure she can go through with it."

The friend added: "The family will consider it. If it's felt that there's a chance of it helping to find Madeleine then, of course, they will do it. But given it is a year on, you have to wonder about the value of it."

Kate, 40, a GP, has not returned to work and has remained at home in Rothley, Leicestershire, since her daughter disappeared. Gerry, 39, has returned to work as a heart surgeon.

It is believed that any reconstruction would not be televised, although Clarence Mitchell, the family's spokesman, said Kate and Gerry would welcome an opportunity to take part in a televised Crimewatch reconstruction in Portugal if it helped find four-year-old Madeleine.

The couple will not be travelling back to Portugal to mark the anniversary of Madeleine's disappearance on May 3 if they remain arguidos - formal suspects.

Producers from Crimewatch had put forward a request to do a reconstruction within the first month of Madeleine's disappearance.

But it is understood that due to the secrecy of Portuguese law, this offer was turned down by police officers.