By Michael Holden

LONDON (Reuters) -An alleged sex assault victim of Kevin Spacey said the "slippery" Hollywood actor had tried to "groom" him, and the repeated groping assaults had left him feeling physically sick, a London court heard on Monday.

Spacey, 63, is on trial at Southwark Crown Court accused of a dozen allegations of historic sex offences committed against four men, then aged in their 20s and 30s, which are said to have taken place between 2001 and 2013.

He has denied all the charges and his lawyer Patrick Gibbs said last week at the start of the trial the jury were going to hear some "damned lies".

On Monday, the court was shown a recorded police interview with the first of the alleged victims. The man said the actor had assaulted him on up to 12 occasions over a period of about four years in the early 2000s, grabbing his "private areas" when they were alone, such as in a car or an elevator.

After two to three weeks of being with Spacey, the actor made him feel uncomfortable, rubbing the man's legs and neck while he was driving, before later starting to grope him or force the man's hand onto his genitalia, he said.

"He was almost, from the get go, grooming me," the man said in the interview.

The alleged victim, who cannot be identified, said the "touchy feely" actor had on one occasion aggressively grabbed his crotch so hard when he was driving him to a party hosted by singer Elton John in about 2004 that he almost crashed the car.

Describing himself a "man's man", the accuser recounted that he had threatened to knock the actor out if he did it again, to which Spacey had replied "that's such a turn on to me".

He described the Oscar-winner as a "slippery snaky, difficult person", a "mixed-up individual" who was very confused about his sexuality. The man said Spacey's behaviour was an open secret at the London Old Vic theatre where he worked for more than a decade.

"It was well-known that he was obviously up to no good so to speak," the man said.

'SICK'

Giving evidence in person in court from the behind a screen, the man said he felt shocked, embarrassment and ashamed about what had happened to him, saying the alleged assaults made him feel physically sick.

He rejected suggestions from Spacey's lawyer Gibbs that he had been flirtatious himself with the actor, had appeared to enjoy the interaction and that he had questioned his own sexuality.

Gibbs quizzed him about why he had kept a "warm and jolly" letter Spacey had sent him ahead of a charity event the man was involved in, and a "cosy" photo he posted on social media showing him with the actor.

"It’s just a normal photo, two men standing next to each other," the witness replied.

Gibbs also put it to him the allegation regarding the incident prior to the Elton John party was completely untrue, pointing out that Spacey had only attended one such gathering which was in 2001. The man replied he might have got the dates wrong as it had been so long ago.

Asked why he had only come forward to the police last year, he said it was the "right time", and then when questioned whether it had occurred to him he might be able to sue Spacey, he agreed it had.

Asked how much he thought he might receive, he replied: "Whatever it would be, it wouldn't be enough for somebody who had been assaulted and abused."

The trial is due to last about four weeks.

(Reporting by Michael Holden, Editing by William Maclean)