Madeleine McCann: Robert Murat 'facing questions as witness'

Madeleine McCann pictured on the day she went missing in 2007

Portuguese police investigating the disappearance of British girl Madeleine McCann are to question former suspect Robert Murat, the BBC has learned.

A source close to the case has told the BBC that Mr Murat, one of 11 people being interviewed by officers in Portugal, will be treated as a witness.

He has always denied any involvement in the disappearance and said that his conscience "is clear".

Madeleine was three when she went missing in Praia da Luz in May 2007.

Mr Murat was the first person to be declared a suspect or 'arguido' in the investigation and was later cleared by police in Portugal.

He won substantial damages from various media organisations and has always denied any involvement in Madeleine's disappearance.

'Conscience clear'

Speaking to the BBC from the Algarve, Mr Murat said neither he nor his lawyer had received a formal request to appear, but said he "would do so freely".

He said: "My conscience is clear and I have no problem speaking to the police again."

Mr Murat's wife has also been listed as one of the four witnesses the Metropolitan Police wish to have questioned regarding Madeleine's disappearance.

Four of the 11 speaking to police are being interviewed as witnesses and seven as 'arguidos' - a status in the Portuguese judicial system referring to individuals whom police may reasonably suspect are linked to a crime.

Mr Murat and his wife are understood to be due to speak to police

British detectives had been scheduled to fly out to observe the questioning next week, but this was postponed on Tuesday night, believed to be due to legal technicalities.

British police can sit in on the interviews but are not allowed to ask direct questions.

In June, Portuguese and British police searched three sites in the Algarve resort but found no evidence relating to the case.

The following month, four suspects, all Portuguese citizens, were questioned by Portuguese detectives in Faro but this led to no new developments.

The interviews were observed by officers from the Met Police, which is conducting its own investigation.

The McCann family were staying in an apartment in the Algarve resort of Praia da Luz when Madeleine went missing. Her parents had been at a restaurant near their apartment that evening.

The Met launched a fresh investigation into Madeleine's disappearance, codenamed Operation Grange, in July 2013.

The request to interview the 11 people of interest comes from Letters of International Request submitted to Portugal's Attorney General by British detectives from the operation.

A Metropolitan Police spokesman said: "Scotland Yard is not prepared to provide a running commentary."