Hong Kong - A police report into an alleged assault by the wife of Zimbabwean president Robert Mugabe on a Hong Kong photographer has been sent to the city's Department of Justice to decide whether she should be prosecuted, police said Sunday.

Hong Kong police are understood to believe they have sufficient evidence to prosecute after two vital witnesses were traced following the incident involving Zimbabwe's First Lady Grace Mugabe on January 15, according to a source familiar with the case.

However, police officers involved in assessing the case have also raised the question of whether Ms Mugabe might claim diplomatic immunity if any proceedings are brought, the source told Deutsche Presse-Agentur dpa.

Richard Jones, chief photographer with Hong Kong's Sinopix photo agency, claims he was repeatedly punched by 43-year-old Ms Mugabe after he took pictures of her shopping during a visit to the city where her daughter Bona is a university student.

Welshman Jones, 42, said he suffered bruises and cuts on his face and forehead inflicted in part by a diamond-encrusted ring she was wearing as she allegedly attacked him with a bodyguard and tried to wrestle his camera from him.

Jones reported the alleged assault to police on January 17, by which time Ms Mugabe and her entourage had checked out of their five-star hotel and returned to Zimbabwe. It is not known if Ms Mugabe has been contacted by Hong Kong police since her return.

It was initially thought the incident might have been captured by a security camera on the side of a shopping centre but the source said police found the event took place just out of the camera's range.

However, since the investigation was launched, two witnesses - an Austrian tourist and a Hong Kong resident - have been traced and have given detailed statements to police about the alleged assault, the source said.

The Austrian tourist is said to have watched "open-mouthed" as the incident unfolded and is understood to have given a statement that confirms Jones's version of events.

A spokesman for Hong Kong police declined to comment on details of the investigation into the alleged assault or to say if any attempt had been made to contact Ms Mugabe or whether she would face extradition proceedings over the incident.

The spokesman would not respond to questions about whether Ms Mugabe would be arrested or questioned if she returned to Hong Kong. He said in a statement: "No arrest has been made so far. The case has been referred to the Department of Justice for advice."

Jones was working for the Sunday Times newspaper in the UK when the incident in Tsim Sha Tsui took place. The same newspaper last week carried a report claiming Robert and Grace Mugabe had bought a 5 million US dollar home in the city and that Grace had held talks over a diamond cutting and polishing venture while in Hong Kong.

Two other Hong Kong-based photographers working for the newspaper - American Tim O'Rourke and Briton Colin Galloway - were allegedly assaulted nine days ago outside the Hong Kong property by two men and a woman understood to be employed as bodyguards.

The police spokesman said investigations into the Tai Po case were continuing. "The case is classified as alleged common assault. No arrest has so far been made and legal advice will be sought in due course." (dpa)