The Conservative MP, who is the half-brother charged with alleged historic sex abuses, has said he had "no knowledge" of the claims.
John Whittingdale added that he was "aware" Charles Napier had been charged with an offence alleged to have occurred over 35 years ago.
Mr Whittingdale said: "I have no knowledge of this, particularly as I had only just left school at that time.
"However, obviously I recognise that this is a serious matter and that the law must take its course."
More top news
Weather set to improve with plenty of sunshine by Saturday
Tony Davis was the first civilian to reach Pc Palmer after he was stabbed during the Westminster attack.
Defiant Londoners put on a show of solidarity for the victims of the Westminster terror attack at a vigil in their honour.