Scotland Yard will not launch a criminal investigation into BBC journalist Martin Bashir’s interview with Diana Princess of Wales.

The Metropolitan Police said “no further action” will be taken over allegations connected to the Panorama programme broadcast in 1995.

A former employee of Earl Spencer, who claims he was the subject of false documents allegedly used to gain access to Diana, had earlier made a formal complaint to the force.

A legal representative of Alan Waller, who used to work for Diana’s brother Earl Spencer as head of security, wrote to the Met alleging unlawful activity.

Commander Alex Murray said on Thursday: “In recent months the Metropolitan Police Service received correspondence alleging unlawful activity in connection with a documentary broadcast in 1995. This was carefully assessed by specialist detectives.

“They obtained legal advice from Metropolitan Police lawyers, independent counsel and from the Crown Prosecution Service.

“Following this detailed assessment and in view of the advice we received, we have determined that it is not appropriate to begin a criminal investigation into these allegations. No further action will be taken.

“In this matter, as in any other, should any significant new evidence come to light we will assess it.”

It has been alleged that Bashir used two mocked-up bank statements to falsely show Mr Waller was receiving payments as a way to persuade the earl to give him access to Diana.

The BBC has previously said in a statement that during an internal corporation investigation in 1996, Mr Bashir admitted commissioning mocked-up bank documents.

They had been shown to Earl Spencer, but he said they had played no part in securing the princess’s appearance on Panorama.

Earl Spencer has alleged Bashir showed him fake financial documents relating to Diana’s former private secretary Patrick Jephson, and another former royal household member, and told outlandish and untrue stories about the royal family to gain access to his sister.

His claims have led the BBC to appoint Lord Dyson, former Master of the Rolls and head of civil justice, to lead a new independent investigation, which has already begun, to discover what steps the BBC and Bashir took to land the interview with Diana.