A 23-year-old man has been arrested on suspicion of rape following an alleged incident inside Britain's Houses of Parliament, London police said on Tuesday, according to Reuters.

The attack reportedly took place in the early hours of last Friday and the suspect, who police have not named, was detained later that day, Reuters reported noting that police said he was not a lawmaker.

Police said the man had been released on bail until January pending further inquiries.

A spokesman for the House of Commons, one of Britain's most recognizable buildings on the banks of the River Thames in Westminster, said they were aware of the incident and parliament was working closely with police.

Meanwhile, citing Metropolitan police The Guardian reported on October 18 that Craig Mackinlay staff member, 23, was granted bail after being detained over alleged attack in early hours of Friday.

The 23-year-old man, who works for the Tory MP Craig Mackinlay, has been arrested on suspicion of raping a woman in the Houses of Parliament.

A spokesman for the South Thanet MP said: “On Friday morning, Mr. Mackinlay was made aware of an allegation against a member of his staff.

“Following a request made by the police and parliamentary services he granted full access to his Westminster office.  Mr. Mackinlay is currently awaiting further information from the police.”

Officers were called to Westminster after the alleged victim raised the alarm.  Police said the man had been bailed until January as detectives investigated what happened.

A Met spokesman said: “Detectives from the sexual offences, exploitation and child abuse command are investigating an allegation of rape at the Houses of Parliament in the early hours of Friday, October 14.

“A 23-year-old man was arrested that same day on suspicion of rape.  He has been bailed pending further inquiries to a date in mid-January 2017.”

According to Mirror, reports have named the suspect as 23-year-old Sam Armstrong, the MP's chief of staff and spokesman.