Police were called after drugs were found inside the Home Office's London headquarters, the department has confirmed.
A "small quantity" of suspected class A drugs were discovered in a communal area - reportedly a disabled toilet - at the office on Marsham Street, Westminster, on May 3.
According to the Sunday Mirror, the drugs were believed to be crystal meth.
A spokesman for the Home Office said police had been called by security staff, who discovered the discarded drugs. Officers attended and removed the substance.
The spokesman added: "The police advised no further action was needed.
"We take incidents of this nature extremely seriously, always ensure that proper procedures are followed and take appropriate action based on the advice of the police."
Scotland Yard confirmed officers were called to the incident.
A spokesman said: "The substance was seized by officers and taken to a local police station. Advice was provided to security staff. No suspects have been identified at this time."
The incident came just a few days after Sajid Javid took over from Amber Rudd as Home Secretary.
The Home Office is responsible for government policy on security-related issues such as drugs.