Nightstalker accused Delroy Grant was “serially unfaithful” to his wife and had a string of women, he admitted in court today.

Grant, who is accused of carrying out a campaign of sex attacks and burglaries on elderly victims over the course of 17 years, gave evidence for the first time at Woolwich Crown Court.

The 53-year-old, of Brockley Mews, Brockley, claims his ex-wife Janet planted his semen and saliva using a male associate at the scenes of the attacks, which are linked to Grant by his DNA.

The court heard Grant, who has 10 children from four different women, had a string of relationships with other women and that he accepted he was “serially unfaithful” to his wife Janet.

Grant claimed during their relationship she was seeing someone else and said: “By the time I was getting home, he was leaving the house.”

Grant admitted that this “occasionally” resulted in violence and he and Janet would “fight like cats and dogs”.

The court heard Janet divorced him when he was sent to prison for six years for playing the role of get-away car driver in an attempted robbery on a post office in East Dulwich.

Grant, who admitted the offence, served two years in jail.

Grant moved to England from Jamaica in the 70s when he was 14 or 15 to join his father and stepmother at their home in East Dulwich.

Grant, who attended Kingsdale School in Crystal Palace, said his parents were “good parents but very strict”.

He said he met Janet while he was working at a petrol station in London Bridge and they married at St Lawrence Church in Bromley Road, Catford.

When she found out about his relationship with another woman he said she refused to sleep with him, the jury heard.

Grant said: “She was not going to have sex with me because she was concerned that I had caught something.

“She said the only way that can take place is if I have my saliva and semen tested and she knew someone who could do that who worked at Guys Hospital.”

Grant claimed that in 1977 Janet made him produce semen into six cups and saliva into another cup, which he says she put into two bottles.

Courtenay Griffiths, defending Grant, said: “After you provided these samples what happened?”

Grant replied: “On one occasion someone on a motorbike pulled up downstairs and hooted the horn.

“Janet brought two bottles to this guy, who had a helmet on and a white coat.”

Grant accepted that he was linked to the offences he is charged with by his DNA and that there was a one in a billion chance it matched someone else.

Mr Griffiths said: “You accept that the semen samples observed by forensic scientists came from vaginal swabs?

“Can you help us as to how this unknown man was able to do that.”

Grant replied: “By using instruments, I assume a syringe.”

Grant claimed his ex-wife Janet was motivated by “malice”, “hatred” and from the “violence” and the relationships he’d had.

The jury also heard Grant became a Jehovah’s Witness after meeting his current wife Jennifer who he became a carer for in 2003.

Grant denies 16 burglaries, two attempted burglaries, three rapes, one attempted rape, six indecent assaults, and one sexual assault.

The trial continues.