Boris Johnson’s party has been engulfed in fresh scandal as it emerged another Conservative MP had been arrested on suspicion of serious sexual offenses, including rape.

Iran PressEurope: The unnamed man’s arrest on Monday followed a two-year investigation, Metropolitan police said – and related to offenses alleged to have been committed between 2002 and 2009.

In a statement, the Met said “a man, aged in his 50s, was arrested on suspicion of indecent assault, sexual assault, rape, abuse of position of trust and misconduct in public office. He remains in custody”.

“The offenses are alleged to have occurred in London. An investigation is ongoing, led by officers from Central Specialist Crime.” Westminster sources suggested some of the offenses are believed to have taken place in parliament.

Last May, MP Neil Parish resigned as an MP after admitting he watched porn twice in the House of Commons.