Detectives investigating the murder of an Inverness-born police officer are trying to trace a man seen outside the flat where his body was found in London.

The human remains of PC Gordon Semple, 59, were discovered after a neighbour alerted Scotland Yard to a "smell of death" coming from a property in the Peabody Estate in Southwark Street, south London.

The discovery was made a week after the Met Police officer went missing.

Scotland Yard are appealing for a man spotted outside the flat on April 1, the day Mr Semple went missing, to contact police.

Detective chief inspector Cliff Lyons, from the homicide and major crime command, who is leading the murder investigation, said the man was "only there for a minute" and did not go inside but stressed it is "incredibly important" officers speak to him.

The appeal comes after Stefano Brizzi, 49, appeared via video link at Bromley Magistrates' Court charged with murder.

Italy-born Brizzi is alleged to have committed the murder at his flat on a day between April 1 and April 7.

He appeared calm as he confirmed his name, age and address during the brief hearing. Brizzi, who is bearded, told the court: "I'm an Italian citizen but a UK resident."

Brizzi sat next to a lawyer at a table in Lewisham Police Station and at times leaned forward in his seat as he listened to the proceedings.

No indication of plea was given and the chairwoman of the bench Sue Polydorou remanded him in custody to appear at the Old Bailey on April 13.

Mr Semple was originally from Inverness and had been with the Metropolitan Police for 30 years.

Scotland Yard said "detectives are now satisfied that the human remains found at the address" in Southwark are his.

A first post-mortem did not discover the cause of death, however, and a second one has been ordered and will be carried out on Wednesday April 13.

Mr Lyons said: "I am keen to trace a man who went to Brizzi's flat in Southwark Street on Friday, April 1, at about 3pm. He was there for only one minute, and did not go inside, but it is incredibly important that we speak to him.

"If you are that man please come forward and call us on 020 8721 4961. I will treat what you tell me with sensitivity and confidentiality, please get in touch with us. I need to talk to you."