Police are anxious to speak to the man on the left

The body of Yermia Yunataev, an Israeli in his 40s, was found in a room at the Marriott Hotel, central London, at 2030 BST on 28 March.

CCTV footage shows Mr Yunataev walking with a white man in Gloucester Road, South Kensington, at about 0340 BST, after leaving the Grosvenor Casino.

It is thought Mr Yunataev may have links to the Israeli underworld.

Detectives believe Mr Yunataev may have been murdered by organised criminals, possibly as a result of a drugs deal which went wrong.

Gangland violence has been hitting the headlines in Mr Yunataev's native Israel.

In December two people were killed by an explosion, thought by police to have been aimed at a local figure from the criminal underworld.

Bloody clothes

Police say Mr Yunataev was probably strangled and an inquest, opened and adjourned at Westminster Coroner's Court on 1 April, gave the provisional cause of death as asphyxiation.

The discovery came after bloody clothes and documents from the hotel were found dumped at a Eurotunnel terminal in Kent.

Police believe Yermia Yunataev was strangled or suffocated

Detectives earlier flew to Israel as part of the investigation after being initially baffled as to Mr Yunataev's identity.

He was believed to have had an Israeli passport but is thought to have checked into the hotel under a false name.

The first CCTV image released shows Mr Yunataev after he left the casino, walking along Gloucester Road north towards Cromwell Road, at about 0345 BST on 28 March.

A second image shows him, at the same time and location, with another man.

The other man is described as white, aged about 35, with receding hair.

Police appeal

Mr Yunataev arrived at the Marriott Hotel just after 9am in a black Comcab.

He stayed in the hotel bar for about 45 minutes before taking the hotel lift.

His body was found in his room on the seventh floor later that day.

Police have urged the man in the CCTV images and the black cab driver to come forward.