Police forensic experts have been carrying out tests on items seized from the luxury hotel room where a couple killed themselves with cyanide in a suicide pact.

Post-mortem examinations are being carried out on the bodies of a man and woman, said to be Russian, who were found in a room by staff at the five-star Scotsman Hotel in Edinburgh, alongside containers of chemicals, prompting a major emergency response.

Police said the unexplained deaths followed a "chemical incident" but have so far not named the victims

One report said the couple were from Russia and left a note saying they had taken the poison, while hotel guests noticed a strong smell "like sewage" before the bodies were found.

The discovery on the sixth floor prompted a response by the Scottish Fire and Rescue chemical incident team, with around 25 specialist firefighters sent to the scene.

The sixth floor was evacuated and a large cordon put in place outside the hotel entrance in North Bridge, yards from the historic Royal Mile and a short distance from Princes Street, the city's main shopping thoroughfare.

Police said on Friday night that they had finished their inquiries within the hotel room and a number of items have been seized by officers to go under forensic tests.

A force spokesman said the deaths are still being treated as unexplained but early indications pointed to a "chemical-related incident".

Guests staying at the hotel who were evacuated during the investigation have now been allowed to return.

Chief Inspector Murray Dykes said: "Since Police Scotland and our partners became involved in this incident, our intention was, and continues to be, keeping the public safe from harm and returning a sense of normality to the hotel and surrounding area.

"Our inquiries within the room have now concluded and all items collected from inside will undergo thorough examination to help us determine how both individuals died.

"They, their families and loved ones are very much in our thoughts as we carry out our policing duties.

"I would also like to issue my sincere thanks to all guests at the Scotsman Hotel, whose stay may have been interrupted as a result of our presence. In addition, the co-operation and assistance of all hotel staff has been excellent during an extremely difficult and sensitive time.

"While our investigation will continue, business can return to normal at the hotel and I would again stress that there is no risk to anyone who is, has or will visit the Scotsman Hotel."

The spokesman added that the names of the man and woman will not be released until their families have been informed.