A former aide to Prime Minister David Cameron has been cleared on two counts of downloading pictures of scantily clad under-age girls.
Patrick Rock, 65, denies a further 18 charges of making an indecent photograph of a child.
Rock, of Fulham, south-west London, said the 20 images he downloaded to his computer over three days in August 2013 were not indecent.
The jury at Southwark Crown Court took more than six hours to return not guilty verdicts on two of the charges.
Judge Alistair McCreath directed the jurors that majority verdicts could be accepted on the remaining counts and they retired to continue their deliberations.
Jurors were told on Tuesday they would have to decide whether the pictures broke the law.
They were shown the images, which featured identified girls aged 10 to 16 posing in clothing including bikinis, hot pants and a bra, suspenders and a ballet tutu.
The prosecution argued the images showed girls, although not naked, in "sexual" poses that drew attention to their genital and breast areas.
But Rock's defence lawyer, Sasha Wass QC, compared the images to Britney Spears' video for her 1998 song Baby One More Time, which she made when she was 16.