The man believed to be Britain's most notorious serial sex attacker was arrested by the Metropolitan Police last night.

Known as the ‘Night Stalker’, the man is thought to be responsible for 108 offences in south and south-east London, including four rapes and 24 indecent assaults. He breaks into homes and sexually assaults his elderly victims.

Yesterday morning a 52-year-old man was arrested in south London — the area where most of the attacks took place. He is being held at a police station in the capital. His arrest is described as “significant” and charges are expected today.

One senior detective described the case as “the biggest in the Met's history”. At least one high-ranking officer is said to have personally checked the DNA database daily in the hope that someone arrested overnight on an unrelated offence provided a match.

Yesterday's arrest resulted from a targeted operation against the individual police think is responsible. The case of the Night Stalker has baffled detectives at Scotland Yard since 1990.

The police have had a DNA sample for 12 years after compiling forensic evidence from at least 10 crime scenes.

Forensic investigations showed that both of his parents originally came from the Windward Islands in the Caribbean. Officers carried out 2,054 tests at a cost of £102,700 but have never found a match on the DNA database.

A team of 29 police officers and staff based at Lewisham police station drew up a list of 21,500 suspects and began asking men for voluntary DNA samples.

Officers also travelled to Caribbean islands including Trinidad, Tobago and St Vincent.

Because of his apparent ability to avoid detection the police even suspected he could be a former police officer.

Some of his victims, men and women aged between 68 and 93, have been raped and sexually assaulted. The total number of raids linked to the man during his 19-year reign is at least 108.