Juergen Mathies
Juergen Mathies said that CCTV footage did not allow sex attackers to be clearly identifiedGetty

Most of the men who sexually assaulted women in Cologne on New Year's Eve may never face justice, the city's police chief Juergen Mathies told the BBC. The admission came as the trials of three men accused of robbery on the night began on 24 Febuary.

Mathies said that CCTV footage was not good enough to identify sex assaults. More than 400 women claim to have been sexually assaulted in the city during New Year's Eve celebrations, with police identifying 75 mainly North African refugee suspects.

"The CCTV footage is not good enough to clearly identify sexual assaults. We can see some thefts but that's all. We are relying on witness accounts and victims identifying their attackers," said Mathies.

None of the three men to stand trial in Cologne are charged with sexual offences. One of the men is charged with stealing a phone from a woman, while the other two are charged with stealing a camera from a man.

Only one person, a 26-year-old Algerian asylum seeker, has been arrested for alleged sex offences on New Year's Eve.

Cologne's previous police chief was sacked amid allegations that police had tried to cover up the attacks. An official report into police handling of the incident found significant failings, with officers failing to call for reinforcements or inform the public of the situation.